- Boost-users - lists.preview.boost.org

[boost-users][system] Mixing non-errors and errors (status_code vs. error_code)
by Darren Garvey 15 Oct '07

15 Oct '07

Hello, I've been wondering for a while if it's sensible to use Boost.System for transporting status_codes, rather than strictly error_codes. I'm aware than I *may* be trying to misuse the system library here, so I'll get straight to an example: If I had an HTTP library that retrieved remote pages, I might want to use, as (a very crude) example: template<typename MutableBufferSequence> void get_page(http::connection& conn, MutableBufferSequence& buf) { boost::system::error_code ec; conn.get_page(buf, ec); if (ec) throw ec; } The problem with relying on error_code to carry the errors is that the various success codes (eg. 200 OK, 201 ACCEPTED, 202 CREATED, etc.) seem to get lost, unless you class them as errors. Then you'd need something like: - if (ec) throw ec; + if (ec >= http::ok || ec <= http::multi_status) throw ec; It's not a massive pain, but having `ec == true` even when you don't have an error isn't helpful. AFAICT, any non-zero error value is an error that'll give `ec == true`. I feel like I'm missing something here, please tell me if I am. Regards, Darren PS. I'm trying to avoid having to make something that lies on top of boost::system::error_code, like a status_code class.

1 0

[Serialization] Example for Boost.Any
by Joseph Lisee 15 Oct '07

15 Oct '07

Hello, 2 years ago on this list there was a discussion on how to serialize/deserialize a Boost.Any variable. I read through and found some proposals, but never any implementations. I was wondering whether anyone had ever gotten around to implementing it? I have no qualms about using a custom Boost.Any with serialization support coded in. -Joe

1 0

what::runtime_error::std already defined
by Lars Schouw 15 Oct '07

15 Oct '07

I am getting these linking errors and can't figure out where it comes from. 4>libboost_regex-vc80-mt-gd-1_34_1.lib(instances.obj) : error LNK2005: "public: virtual char const * __thiscall std::runtime_error::what(void)const " (?what@runtime_error@std@@UBEPBDXZ) already defined in Curve.obj I am using Visual Studio 2005 SP1 and Windows XP Lars ____________________________________________________________________________________ Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games. http://sims.yahoo.com/

1 0

[program_options] Dynamic linking broken with VS7.1
by Robert Brueckmann 15 Oct '07

15 Oct '07

I tried to compile a simple test program, but it doesn't link dynamically. Any suggestions, what I'm doing wrong? I'm using boost 1.34.1 prebuilt libs from boost-consulting and MSVC 7.1. The test code which fails: #include <boost/program_options.hpp> namespace po = boost::program_options; int main(int argc, char** argv) { unsigned int i1; po::options_description normal_options("parameters"); normal_options.add_options() ("test,t", po::value<unsigned int>(&i1)->default_value(0), "test") ; return 0; } I compile using the following command: cl /TP /EHsc /nologo /GR /WL /W2 /Od /MDd /GS /Z7 /DBOOST_ALL_NO_LIB /Ih:\repos\trunk\3rd\include\common\boost\1_34_1 /c main.cpp /Fomain.obj The linker command link /nologo /OUT:test.exe /LIBPATH:h:\repos\trunk\3rd\lib\win32\cl\13.10\boost\1_34_1 boost_program_options-vc71-mt-gd-1_34_1.lib /DEBUG main.obj fails with the error message main.obj : error LNK2001: unresolved external symbol "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > boost::program_options::arg" (?arg@program_options@boost@@3V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A) However, when linking statically using link /nologo /OUT:test.exe /LIBPATH:h:\repos\trunk\3rd\lib\win32\cl\13.10\boost\1_34_1 libboost_program_options-vc71-mt-gd-1_34_1.lib /DEBUG main.obj then everything is working... Any ideas? Thank you in advance, Robert

1 0

[Iostreams] stream not clearing state
by Benjamin Collins 14 Oct '07

14 Oct '07

I'm trying to use a stream and open/close the underlying device on the fly. Here's my test code: #include <iostream> #include <boost/filesystem.hpp> namespace fs = boost::filesystem; #include <boost/iostreams/device/mapped_file.hpp> #include <boost/iostreams/stream.hpp> namespace io = boost::iostreams; namespace { const uint32_t block_size = io::mapped_file_source::alignment(); } bool test1() { io::mapped_file_params mfp("rand.bin"); mfp.mode = std::ios_base::in | std::ios_base::binary; mfp.length = block_size; io::mapped_file mf(mfp); io::stream<io::mapped_file> in(mf); int blocks = fs::file_size("rand.bin")/block_size; if (fs::file_size("rand.bin") % block_size) ++blocks; for (int i=0;i<blocks;++i) { in->close(); mfp.offset = block_size*i; std::cout << "mapping bytes [" << block_size*i << " - " << block_size*(i+1) - 1 << "]\n"; in->open(mfp); in.clear(); std::cout << "stream is in state: [ "; if(in.rdstate() | std::ios::goodbit) std::cout << "good "; if(in.rdstate() | std::ios::badbit) std::cout << "bad "; if(in.rdstate() | std::ios::failbit) std::cout << "fail "; if(in.rdstate() | std::ios::eofbit) std::cout << "eof "; std::cout << "]\n"; int count=0; char x; while(!in.eof()) { if(io::stream<io::mapped_file>::traits_type::eof() == (x = in.get())) throw std::runtime_error("unexpected eof"); std::cout << '.'; ++count; } if(0==count) throw std::runtime_error("unable to read characters in this map"); else std::cout << count << "bytes read.\n"; } } If you don't like to see code in email, see here: http://pastebin.com/m40e9432b This program prints the following: ------------------------------------------------ mapping bytes [0 - 4095] stream is in state: [ bad fail eof ] terminate called after throwing an instance of 'std::runtime_error' what(): unexpected eof Aborted So what gives? Why isn't boost::iostreams::stream clearing its state properly? -- Benjamin A. Collins <ben.collins(a)acm.org> http://bloggoergosum.us

1 0

[BGL] Inverse property mapping?
by "Alejandro M. Aragón" 14 Oct '07

14 Oct '07

Hello everyone, I've been looking for some time at the documentation and I couldn't find a single way to obtain an inverse mapping for a property map. That is, given a property p, I would like to obtain a vertex descriptor v. It seems that the mapping is only in one direction. Is there a way to obtain the inverse mapping too? If so, what is the complexity associated with obtaining the vertex descriptor? Thank you, a²

3 3

[serialization]-- boost integrated with MFC Doc/View?
by Rich Peters 13 Oct '07

13 Oct '07

I am looking at boost serialization and it looks very good. Has anyone tried to integrate boost serialization with MFC Doc/View CArchive serialization? I would be interested to hear how you did it. Can a CArchive be turned into a istream or ostream that could be used? thanks

2 1

ptr_set problems
by Surya Kiran Gullapalli 13 Oct '07

13 Oct '07

Hello, I'm using ptr_set for one of my classes whose structure is like this. =============================== using namespace boost; class A: less_than_comparable<A>, equality_comparable, noncopyable { friend operator< (const A&, const A&) ; public: A() virtual ~A () virtual void fun1() = 0 ; } class B: public A { public: B () ; ~B () ; virtual void fun1() { cout << "Func1 in B" << endl ; } } class C : public A { public: C () ; ~C () ; virtual void fun1() { cout << "Func1 in C" << endl ; } } ============================================== and I'm inserting into ptr_set like this. A *varb = new B () ; A *varc = new C() ; ptr_set <A> Aset ; Aset.insert (varb) ; Aset.insert (varc) ; **************** Compilation is fine on windows (VS2005) and linux (gcc-4.1.2) On linux, the code executes fine. But on windows, I'm getting a DEBUG ASSERTION failure during insertion. The failure says, Expression: invalid operator<. This happens in debug version only. In release version, the code executes fine on windows also. Any help on how to attack this problem is greatly appreciated. Thanks in advance, Surya

2 1

Making an ordinary function into something useful in lambda expressions
by Peter Waller 13 Oct '07

13 Oct '07

I wish to write some lambda functions to have this sort of behaviour. #include <lambda/lambda.hpp> #include <lambda/bind.hpp> #include <function.hpp> using namespace boost::lambda; using namespace boost; #include <iostream> using std::cout; using std::endl; #include <cmath> int main( int argc, char *argv[] ) { float value; var_type<float>::type theValue( var( value ) ); // Ignore this line #define cos(theta) bind( unlambda(bind( cos, _1 )), theta ) function<float ( float )> myfunction = ( cos( theValue ) - 1 ); value = 2; cout << "The result = " << myfunction(1) << endl; return 0; } Namely, the cos( value ) part. The code above works, but I feel that using a #define is a little messy, and seems hard to generalise to functions with more arguments. I was wondering if there was a general, better way of turning a given function into one whose execution is delayed. Thanks in advance, - Peter

3 3

[boost-users][function, assign] error C2986 and C2784 on visual studio 2005 .
by chun ping wang 13 Oct '07

13 Oct '07

So given this header. template < QSTYPE type, typename T, template <typename ELEM, typename = std::allocator<ELEM> > class CONT > CONT<T> quicksort(CONT<T>); // inside the main file. // I decided a function that takes vector of integer and returns a vector of integer. typedef boost::function<std::vector<int>(std::vector<int>)> sortfunc; // create a function list to hold the sorting function. // bunch of number include. #include <boost/assign/std/vector.hpp> std::vector<sortfunc> function_list; using boost::assign::operator+=; std::vector<sortfunc> function_list; // quicksort random function_list += (&algocpw::quicksort<algocpw::QSTYPE(algocpw::RANDOM), int, std::vector>), // quicksort median (&algocpw::quicksort<algocpw::QSTYPE(algocpw::MEDIAN), int, std::vector>), // quicksort mediantriple (&algocpw::quicksort<algocpw::QSTYPE(algocpw::MEDIANTRIPLE), int, std::vector>), // merge sort (&algocpw::mergesort<int, std::vector>), // heap sort (&algocpw::heapsort<int, std::vector>), // selection sort (&algocpw::selection_sort<int, std::vector>), // standard sort (&algocpw::standard_sort<int, std::vector>); I get the following errors. ./cs512/c++/sortingMain.cpp(63) : error C2896: 'boost::assign::list_inserter<boost::assign_detail::call_push_back<std::vector<_Ty,_Alloc>>,V> boost::assign::operator +=(std::vector<_Ty,_Alloc> &,V2)' : cannot use function template 'CONT<T> algocpw::mergesort(CONT<T>)' as a function argument c:\cpw\msvc\cs512\c++\def\../sortingAlgo.hpp(32) : see declaration of 'algocpw::mergesort' ./cs512/c++/sortingMain.cpp(63) : error C2784: 'boost::assign::list_inserter<boost::assign_detail::call_push_back<std::deque<T,Allocator>>,V> boost::assign::operator +=(std::deque<T,Allocator> &,V2)' : could not deduce template argument for 'std::deque<T,Allocator> &' from 'std::vector<_Ty>' with [ _Ty=sortfunc ] Where did "deque" come from.. i never included deque.

1 0

[ANN] Xpressive 2.0.0
by Eric Niebler 12 Oct '07

12 Oct '07

Xpressive has just reached 2.0! The new version has lots of cool new features (see below). Subversion and the File Vault both have the latest code. It works with HEAD and with Boost v1.34.1. Below is an earlier message announcing the feature set of xpressive 2.0. The latest docs are here: http://boost-sandbox.sourceforge.net/libs/xpressive/doc/html/index.html Also, xpressive.zip in the File Vault (Strings - Text Processing directory) contains the docs in pdf format. Please grab the latest code and let me know of any problems you encounter so I can get them fixed for 1.35. -- Eric Niebler Boost Consulting www.boost-consulting.com Eric Niebler wrote: > It's a poorly kept secret that I've been adding new features to > Xpressive on CVS HEAD for a while now. So here are the features already > implemented (documentation forthcoming) for Xpressive 2.0: > > << Semantic Actions >> > > Specify code to execute when parts of a regex match, a-la Spirit's > semantic actions. Eg.: if you want to parse a string of name/value pairs > into a std::map, you might: > > std::map<std::string, int> result; > std::string str("aaa=>1 bbb=>23 ccc=>456"); > > // Like "(\\w+)=>(\\d+)": > sregex pair = ( (s1= +_w) >> "=>" >> (s2= +_d) ) > [ ref(result)[s1] = as<int>(s2) ]; > sregex rx = pair >> *(+_s >> pair); > > if(regex_match(str, rx)) > { > assert(result["aaa"] == 1); > assert(result["bbb"] == 23); > assert(result["ccc"] == 456); > } > > The actions are placed on a queue and executed in order only when the > regex match succeeds. > > << Custom Assertions >> > > Use the check() function to create a boolean predicate that can > participate in the match. Here's a regex that recognizes two integers > only if the first is less than the second: > > sregex rx = ( (s1= +_d) >> ' ' >> (s2= +_d) ) > [ check( as<int>(s1) < as<int>(s2) ) ]; > > Unlike actions, predicates execute immediately. You can also define the > predicate out-of-line as a function object. > > << Dynamic Regex Grammars with Named Regexes >> > > Using regex_compiler, you can map a name to a regex object, and then > refer to that regex from another by name. In this way, you can build > grammars from regexes at runtime. > > sregex_compiler comp; > sregex rx = comp.compile("^bar(?$RE)baz$"); > comp.compile("(?$RE=)\\d+ \\d+"); > > There's an alternate syntax for associating a name with a regex that you > can use to nest a static regex in a dynamic one. Eg., the last line > above could be: > > comp["RE"] = +_d >> ' ' >> +_d; > > With these changes, you can now nest static and dynamic regexes within > each other freely, giving you lots of flexibility to build grammars and > modify them on the fly. > > << Named Captures >> > > For dynamic regular expressions, you can create a named capture with > (?P<name> ...). You can refer back to the named capture with (?P=name). > In substitution strings (for use with regex_replace()), you can refer > back to a named capture with \\g<name> when using the format_perl or > format_all flags. > > And more .... I'd like to give props to Dave Jenkins who has been doing > m4d things with this stuff already, and who has given me a laundry list > of other features he'd like.

1 0

Re: [Boost-users] Container iteration macro that is equivalent tohandcoded iteration?
by John Femiani 12 Oct '07

12 Oct '07

> -----Original Message----- > From: John Femiani > Sent: Wednesday, October 10, 2007 3:16 PM > To: 'boost-users(a)lists.boost.org' > Subject: RE: [Boost-users] Container iteration macro that is equivalent > tohandcoded iteration? > > > > -----Original Message----- > > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > > bounces(a)lists.boost.org] On Behalf Of Michael Marcin > > Sent: Wednesday, October 10, 2007 1:07 PM > > To: boost-users(a)lists.boost.org > > Subject: Re: [Boost-users] Container iteration macro that is equivalent > > tohandcoded iteration? > > > > Erik wrote: > > > I have a lot of handcoded loops that look something like this: > > > > > > //////////////////////////////////////////////////////////////////////// // > > //// > > > #include <vector> > > > > > > void f(float); > > > void g(std::vector<float> const & v) { > > > std::vector<float>::const_iterator const v_end = v.end(); > > > for (std::vector<float>::const_iterator it = v.begin(); it != > v_end; > > ++it) > > > f(*it); > > > } > > > > > > //////////////////////////////////////////////////////////////////////// // > > //// > > > > > > I need to replace it with something equivalent but simpler. I tried > > > BOOST_FOREACH (from boost-1.34): > > > > > > //////////////////////////////////////////////////////////////////////// // > > //// > > > #include <boost/foreach.hpp> > > > > > > #include <vector> > > > > > > void f(float); > > > void g(std::vector<float> const & v) { > > > BOOST_FOREACH(float i, v) > > > f(i); > > > } > > > > > > //////////////////////////////////////////////////////////////////////// // > > //// > > > > > > But when I compared the assembly output of this with that of the > > > handcoded version I discovered that the boost version is more > > > complicated, so I tried to create something better myself, with the > > > requirement that the generated code is not allowed to be any more > > > complicated than that of the handcoded loop. The following is the best > I > > > could think of right now: > > > > > > //////////////////////////////////////////////////////////////////////// // > > //// > > > #define iterate_vector_const(value_type, it, v) > \ > > > for > \ > > > (struct { > \ > > > std::vector<value_type>::const_iterator current; > \ > > > std::vector<value_type>::const_iterator const end; > \ > > > value_type const & operator*() {return *current;} > \ > > > } it = {v.begin(), v.end()}; > \ > > > it.current != it.end; > \ > > > ++it.current) > \ > > > > > > #include <vector> > > > > > > void f(float); > > > void g(std::vector<float> const & v) { > > > iterate_vector_const(float, it, v) > > > f(*it); > > > } > > > > > > //////////////////////////////////////////////////////////////////////// // > > //// > > > > > > I looked at the difference between my macro and the handcoded loop: > > > $ diff -U2 iteration-handcoded-g++-4.2.0-O3.S iteration- > iterate_vector- > > g++-4.2.0-O3.S > > > --- iteration-handcoded-g++-4.2.0-O3.S 2007-10-07 19:38:56.000000000 > > +0200 > > > +++ iteration-iterate_vector-g++-4.2.0-O3.S 2007-10-07 > > > 20:00:53.000000000 +0200 > > > @@ -1,3 +1,3 @@ > > > - .file "iteration-handcoded.cc" > > > + .file "iteration-iterate_vector.cc" > > > .text > > > .align 2 > > > @@ -18,7 +18,7 @@ > > > .LCFI4: > > > movl 8(%ebp), %eax > > > - movl 4(%eax), %esi > > > movl (%eax), %ebx > > > - cmpl %ebx, %esi > > > + movl 4(%eax), %esi > > > + cmpl %esi, %ebx > > > je .L4 > > > .p2align 4,,7 > > > > > >>From this I conclude that my macro is as good as a handcoded loop. > > > (Although I of course wonder why the compiler chose to move "movl > > > 4(%eax), %esi" further down and swap the parameters of cmpl from > "%ebx, > > > %esi" to "%esi, %ebx".) > > > > > > But my macro is not as versatile as BOOST_FOREACH. Is there any way to > > > improve it? In particular, is it possible get rid of the macro > parameter > > > value_type? Is it possible to make it work with other containers than > > > vectors, as long as they define const_iterator/iterator, begin, end > and > > > value_type? Something like this maybe: > > > > > > //////////////////////////////////////////////////////////////////////// // > > //// > > > #define iterate_container_const(it, v) > \ > > > for > \ > > > (struct { > \ > > > typeof(v)::const_iterator current; > \ > > > typeof(v)::const_iterator const end; > \ > > > typeof(v)::value_type const & operator*() {return *current;} > \ > > > } it = {v.begin(), v.end()}; > \ > > > it.current != it.v_end; > \ > > > ++it.current) > \ > > > > > > #include <vector> > > > > > > void f(float); > > > void g(std::vector<float> const & v, std::list<float> const & l) { > > > iterate_containter_const(it, v) > > > f(*it); > > > iterate_containter_const(it, l) > > > f(*it); > > > } > > > > > > //////////////////////////////////////////////////////////////////////// // > > //// > > > > > > Or is it possible to configure BOOST_FOREACH to be as efficient as my > > macro? > > > > I don't know but that is a good question. > > > > I considered using BOOST_FOREACH until I checked its generated output... > > which was worse than std::for_each with a boost::bind which was worse > > than std::for_each with a hand coded functor which was worse than a hand > > coded for loop like yours above. > > > > - Michael Marcin > > > > p.s. Compilers make me sad > > > > _______________________________________________ > > Boost-users mailing list > > Boost-users(a)lists.boost.org > > http://lists.boost.org/mailman/listinfo.cgi/boost-users > > I think you will need to pass SOME type unless you are comfortable with > BOOST_AUTO or BOOST_TYPEOF. I think the problem is on some compilers they > require each type to be 'registered'. > > Maybe if you use a NEXT macro as well things will work out, because you > can put multiple braces in the next macro. > > #define FOREACH(X, COL, COLT) \ > { \ > COLT& __col__ = (COL); \ > for (iterator_type<COLT>::type __i__ = begin(__col__); \ > __i__ != end(__col__);\ > ++__i__) \ > { \ > X = *__i__; \ > { > > #define NEXT() \ > }\ > }\ > } > > > I haven't tried this, but it seems like one could do: > > #define FOREACH(X, COL) \ > { \ > BOOST_TYPEOF(COL)& __col__ = (COL); \ > BOOST_AUTO(__cur__, boost::begin(__col__)); > BOOST_AUTO(__end__, boost::end(__col__)); > for (; __cur__ != __end__; ++__cur__) \ > { \ > X = *__cur__; \ > { > > #define NEXT() \ > }\ > }\ > } > > Then you could use it like: > > vector<int> vec; > > FOREACH(int x, vec){ > > //do something with x > > }NEXT(); > > Or if BOOST_AUTO doesn't work it is > > vector<int> vec; //vector<int> does not have a comma in the type name! > > FOREACH(int x, vec, vector<int>) { > > //do something with x > > }NEXT(); > > > I have no idea how well BOOST_AUTO will work though. You would also need a > TPL version I think. > > IN my own code I have a special concern because I deal with half_edge > structures where begin()==end() and I need to do a bottom testing loop. > In these cases I made iteration macros for each container: I.e. > > MY_FOREACH_VERTEX_EDGE(e, vertex){ > //e is an edge iterator > }MY_NEXT_VERTEX_EDGE() > > > I found that to be readable. I did not use BGL stuff because I did not > know how to deal with begin() == end(). > > > -- John That is, unless you can understand the magic that makes BOOST_FOREACH work. :) -- John

2 1

Container iteration macro that is equivalent to handcoded iteration?
by Erik 12 Oct '07

12 Oct '07

I have a lot of handcoded loops that look something like this: ////////////////////////////////////////////////////////////////////////////// #include <vector> void f(float); void g(std::vector<float> const & v) { std::vector<float>::const_iterator const v_end = v.end(); for (std::vector<float>::const_iterator it = v.begin(); it != v_end; ++it) f(*it); } ////////////////////////////////////////////////////////////////////////////// I need to replace it with something equivalent but simpler. I tried BOOST_FOREACH (from boost-1.34): ////////////////////////////////////////////////////////////////////////////// #include <boost/foreach.hpp> #include <vector> void f(float); void g(std::vector<float> const & v) { BOOST_FOREACH(float i, v) f(i); } ////////////////////////////////////////////////////////////////////////////// But when I compared the assembly output of this with that of the handcoded version I discovered that the boost version is more complicated, so I tried to create something better myself, with the requirement that the generated code is not allowed to be any more complicated than that of the handcoded loop. The following is the best I could think of right now: ////////////////////////////////////////////////////////////////////////////// #define iterate_vector_const(value_type, it, v) \ for \ (struct { \ std::vector<value_type>::const_iterator current; \ std::vector<value_type>::const_iterator const end; \ value_type const & operator*() {return *current;} \ } it = {v.begin(), v.end()}; \ it.current != it.end; \ ++it.current) \ #include <vector> void f(float); void g(std::vector<float> const & v) { iterate_vector_const(float, it, v) f(*it); } ////////////////////////////////////////////////////////////////////////////// I looked at the difference between my macro and the handcoded loop: $ diff -U2 iteration-handcoded-g++-4.2.0-O3.S iteration-iterate_vector-g++-4.2.0-O3.S --- iteration-handcoded-g++-4.2.0-O3.S 2007-10-07 19:38:56.000000000 +0200 +++ iteration-iterate_vector-g++-4.2.0-O3.S 2007-10-07 20:00:53.000000000 +0200 @@ -1,3 +1,3 @@ - .file "iteration-handcoded.cc" + .file "iteration-iterate_vector.cc" .text .align 2 @@ -18,7 +18,7 @@ .LCFI4: movl 8(%ebp), %eax - movl 4(%eax), %esi movl (%eax), %ebx - cmpl %ebx, %esi + movl 4(%eax), %esi + cmpl %esi, %ebx je .L4 .p2align 4,,7 >From this I conclude that my macro is as good as a handcoded loop. (Although I of course wonder why the compiler chose to move "movl 4(%eax), %esi" further down and swap the parameters of cmpl from "%ebx, %esi" to "%esi, %ebx".) But my macro is not as versatile as BOOST_FOREACH. Is there any way to improve it? In particular, is it possible get rid of the macro parameter value_type? Is it possible to make it work with other containers than vectors, as long as they define const_iterator/iterator, begin, end and value_type? Something like this maybe: ////////////////////////////////////////////////////////////////////////////// #define iterate_container_const(it, v) \ for \ (struct { \ typeof(v)::const_iterator current; \ typeof(v)::const_iterator const end; \ typeof(v)::value_type const & operator*() {return *current;} \ } it = {v.begin(), v.end()}; \ it.current != it.v_end; \ ++it.current) \ #include <vector> void f(float); void g(std::vector<float> const & v, std::list<float> const & l) { iterate_containter_const(it, v) f(*it); iterate_containter_const(it, l) f(*it); } ////////////////////////////////////////////////////////////////////////////// Or is it possible to configure BOOST_FOREACH to be as efficient as my macro?

10 17

[review] Exception - review period extended
by Tobias Schwinger 12 Oct '07

12 Oct '07

The review period of the proposed Exception library has been extended until October 20th. Although several people seemed interested in the submission, we only have two votes, so far. So we really need more votes. Further, I'm concerned about some potential issues, which I wouldn't want to bless into Boost without being sure there has been a thorough investigation (see below). So, I want to encourage you to evaluate the submission, in particular regarding the following questions: 1. Should the library be accepted as a Boost library? For a guideline on what to include in your evaluation see http://www.boost.org/more/formal_review_process.htm 2. Is the design of the 'enable_error_info' function (see http://www.revergestudios.com/boost-exception/boost-exception.htm#existing_… and http://www.revergestudios.com/boost-exception/boost-exception.htm#enable_er… ), using multiple inheritance, really sound? 3. Does the current implementation use appropriate data structures? We are looking forward to your reviews! Regards, Tobias Schwinger - Review Manager -

2 1

[serialization] shared libraries & extended_type_info registration
by Vincent Agnus 12 Oct '07

12 Oct '07

Hi, I have some trouble about extended_type_info registration using BOOST_CLASS_EXPORT macro with shared library. Indeed an assertion forbides the registration of the same extended_type_info many times. This cases occurs when defining serialization of derivated classes in different libraries for example considers the 2 libraries : * the first one define a class and its serialization scheme * the second one define a class derived from the class in the first libs and its serialization scheme A program using this two libraries to serialize classes raise an assertion at runtime due to double registration of the base class [ file serialization/extended_type_info.cpp line 74 // make sure that attempt at registration is done only once assert(lookup(eti) == m_self->m_map.end()); ] Here the detail implementation of libraries LIB1 * files : Base.hpp ; Base.cpp defining a base class ( no serialization code here) * file : BaseSerilization.hxx which contains the definition of the non intrusive template function serialize ( no macro BOOST_CLASS_EXPORT here ) * file BaseSerilizationInstanciation.cpp which explicit instanciate the previous function with a fixed Archive class, this file also contain the macro BOOST_CLASS_EXPORT(Base) LIB2 * file Derivated.hpp, Derivated.cpp defining derivated class from Base ( no serialization code here) * file : DerivatedSerilization.hxx which contains the definition of the non intrusive template function serialize ( no macro BOOST_CLASS_EXPORT here ) ** #include "lib1/BaseSerilization.hxx" ** in fonction serialize .... use of base_object< lib1::Base > * file DerivatedInstanciation.cpp which explicit instanciate the previous function with a fixed Archive class, this file also contain the macro BOOST_CLASS_EXPORT(Derivated) a program using these 2 libraries raise an assertion file serialization/extended_type_info.cpp line 74. Indeed the macro BOOST_CLASS_EXPORT(Base) register the extended_type_info of Base. the macro BOOST_CLASS_EXPORT(Derivated) register the extended_type_info of Base *and* the void_caster register in serialize(... Derivated ...) register *again* Base class raising the assertion. So I have some questions 1. Is my design correct ? My programme work fine (Linux&Windows) in release mode. 2. why forbides multi-registration of the same extended_type_info ? 3. what is the interest using std::multiset for unique element instead std::set for tkmap::m_map type ? Regards, Vincent Agnus

5 9

[signal,bind] upgrade problem from 1.33 to 1.34
by David Angelo 12 Oct '07

12 Oct '07

Hi folks, I have a problem with upgrading from boost version 1.33 to 1.34. My code runs fine with 1.33, but when compiling and linking againt 1.34 I get the following runtime error (backtrace): <backtrace> #0 0x81d4c9b2 in void boost::function1<void, float, std::allocator<void> >::ass ign_to<boost::_bi::bind_t<void, boost::_mfi::mf1<void, fpCTPart, float>, boost:: _bi::list2<boost::_bi::value <fpCTPart*>, boost::arg<1> (*)()> > >(boost::_bi::bi nd_t<void, boost::_mfi::mf1<void, fpCTPart, float>, boost::_bi::list2<boost::_bi ::value<fpCTPart*>, boost::arg<1> (*)()> >)::stored_vtable () from /home/david/eclipseM6/toolManagement/lib/libfpCTToolPack.so #1 0xb4438841 in boost::function0<void, std::allocator<void> >::clear ( this=0xa1a03fc) at /usr/include/boost/function/function_template.hpp:388 #2 0xb4438879 in ~function0 (this=0xa1a03fc) at /usr/include/boost/function/function_template.hpp:313 #3 0xb443889d in ~function (this=0xa1a03fc) at /usr/include/boost/function/function_base.hpp:92 #4 0x81a34c39 in ~holder (this=0xa1a03f8) at /home/david/apps/boost_1_34_1/include/boost-1_34_1/boost/any.hpp:106 #5 0x81137b41 in boost::signals::detail::named_slot_map::insert () from /home/david/apps/boost_1_34_1/lib/libboost_signals-gcc41-1_34_1.so.1.34. 1 #6 0x8113b562 in boost::signals::detail::signal_base_impl::connect_slot () from /home/david/apps/boost_1_34_1/lib/libboost_signals-gcc41-1_34_1.so.1.34. 1 #7 0x81a36e58 in boost::signal0<void, boost::last_value<void>, int, std::less, boost::function<void ()(), std::allocator<void> > >::connect ( this=0x82eac060, in_slot=@0xbfe145f0, at=boost::signals::at_back) ---Type <return> to continue, or q <return> to quit---bt at /home/david/apps/boost_1_34_1/include/boost-1_34_1/boost/signals/signal_template.hpp:286 #8 0x81b359f6 in fpCTPart::initPart (this=0x82eaa7f0) at /home/david/eclipseM6/toolManagement/extensions/fpCTToolPack/parts/src/fpCTPart.cpp:173 </backtrace> Line 173 in fpCTPart.cpp is: geomNode->sigPreLoad.connect(boost::bind(&fpCTPart::slotFilePreLoaded, this)); Are there any changes between these to versions in the bind/signal library? (Are they not backward compatible?) Thanks in advance. Regards, David

1 0

[ptr_map]iterator::reference is not a reference
by Bill Buklis 11 Oct '07

11 Oct '07

I found what seems to be an inconsistency in ptr_map in version 1.34.1 versus 1.33.1. The "reference" typedef in 1.34.1 does not appear to be a reference. The following code illustrates what I mean: typedef std::map<int, int> STDMAP; typedef boost::ptr_map<int, int> PTRMAP; bool isrefstdmap = boost::is_reference<STDMAP::iterator::reference>::value; bool isrefstdbase = boost::is_reference<STDMAP::reference>::value; bool isrefptrmap = boost::is_reference<PTRMAP::iterator::reference>::value; bool isrefptrbase = boost::is_reference<PTRMAP::reference>::value; In version 1.33.1 all bool values equate to true, while in 1.34.1 ptr_map evaluates to false. In case the compiler makes a difference, I'm using VC++ 2005. -- Bill Buklis --

1 0

[boost][range] fusion::begin and boost::begin dont play nice
by John Femiani 11 Oct '07

11 Oct '07

I am using g++ (GCC) 3.4.2 (mingw-special) and when I use the namespace boost::fusion it causes boost range to break. Consider the toy program 'main.cpp', which is attached and also listed below: ----------------------------------------------------------------------- #include <iostream> using namespace std; #include <boost/fusion/sequence/container/vector.hpp> #include <boost/range.hpp> #include <list> int main() { using namespace boost::fusion; using namespace boost; std::list<int> ints; typedef boost::range_iterator<std::list<int> >::type iterator_t; for (iterator_t i = begin(ints); i != end(ints); ++i){ cout << * i << endl; } return 0; } -------------------------------------------------------------------- This program fails to compile with many errors, the first is C:/MSYS/1.0/include/boost/fusion/sequence/intrinsic/begin.hpp:56: error: invalid use of undefined type `struct boost::fusion::extension::begin_impl<boost::fusion::non_fusion_tag>::app ly<const std::list<int, std::allocator<int> > >' If I remove 'using namespace boost::fusion' then everything compiles. This toy program demonstrates an error I got when trying to compile a function that involved both a fusion::vector and std::list. It was easy to work around it in my case by explicitly saying boost::fusion::begin instead of using the namespace, but I suspect that this is still a bug. Please let me know if I misunderstood the correct way to use fusion or range. Thanx, -- John

3 5

Assigning a var() to another var() in a lambda function
by Peter Waller 11 Oct '07

11 Oct '07

Why does this not compile? Should it? It seems quite similar to code found in the section `Naming delayed constants and variables' in the manual at http://www.boost.org/doc/html/lambda/le_in_details.html #include <lambda/lambda.hpp> using namespace boost::lambda; float i = 5, j = 0; var_type<float>::type vi(var(i)), vj(var(j)); #line 172 (vi = vj); The error I get: /usr/include/boost/lambda/detail/lambda_functor_base.hpp: In member function 'boost::lambda::identity<Float_t&>& boost::lambda::identity<Float_t&>::operator=(const boost::lambda::identity<Float_t&>&)': /usr/include/boost/lambda/detail/lambda_functor_base.hpp:23: error: non-static reference member 'Float_t& boost::lambda::identity<Float_t&>::elem', can't use default assignment operator /usr/include/boost/lambda/detail/lambda_functors.hpp: In member function 'boost::lambda::lambda_functor<boost::lambda::identity<Float_t&> >& boost::lambda::lambda_functor<boost::lambda::identity<Float_t&> >::operator=(const boost::lambda::lambda_functor<boost::lambda::identity<Float_t&> >&)': /usr/include/boost/lambda/detail/lambda_functors.hpp:113: note: synthesized method 'boost::lambda::identity<Float_t&>& boost::lambda::identity<Float_t&>::operator=(const boost::lambda::identity<Float_t&>&)' first required here zzNtuple.C: In function 'int main(int, char**)': zzNtuple.C:173: note: synthesized method 'boost::lambda::lambda_functor<boost::lambda::identity<Float_t&> >& boost::lambda::lambda_functor<boost::lambda::identity<Float_t&> >::operator=(const boost::lambda::lambda_functor<boost::lambda::identity<Float_t&> >&)' first required here make: *** [zzNtuple] Error 1 g++ (GCC) 4.1.2 boost 1.34.1 Thanks in advance, - Peter

1 0

Boost 1.35?
by Matt Wharton 11 Oct '07

11 Oct '07

Hello, Does anyone have a _rough_ timetable for when boost version 1.35 will be formally released? Apologies in advance if this question has already been answered or if this is the wrong venue for it. Thanks, -Matt

2 1

Re: [Boost-users] Boost Spirit and C++/CLI
by Hansi Hansi 10 Oct '07

10 Oct '07

What is exactly the error? Which project type you have? What is your entrypoint? Best regards Hansjörg __________________________________________________________________________ Erweitern Sie FreeMail zu einem noch leistungsstärkeren E-Mail-Postfach! Mehr Infos unter http://produkte.web.de/club/?mc=021131

2 1

Re: [Boost-users] regex_search in std::string
by Troy Alexander 10 Oct '07

10 Oct '07

Thanks. That did it. I was focusing on the string to match not the return type. Makes since that they need to be the same type. Troy -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of John Maddock Sent: Wednesday, October 10, 2007 2:44 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] regex_search in std::string Troy Alexander wrote: > The 1st regex_search looking at input_line char[] works Ok it's the > 2nd one looking at date_and_time_s std::string that gets the error. > If I remark out the 2nd one the program builds and I watch the > input_line doing what it should in the debugger. > > Also this code used to work before I upgraded from Visual C++6 to > Visual C++8 and from bost_1_33_1 to boost_1_34_0. I don't know if it > was the change in compiler or the boost lib that broke this. In VC6 this worked "by accident" because const char* and std::string::const_iterator were the same type. That's not true in general, and you should use boost::smatch as the match_results type for use with std::string's. HTH, John. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

[BGL] maximum flow through push_relabel_max_flow
by "Alejandro M. Aragón" 10 Oct '07

10 Oct '07

Hello all, I've been working with the Edmunds & Karp maximum flow algorithm in the BGL for some time without any problems. However, I realized that I could do better in time complexity by moving to the push_relabel_max_flow algorithm so I gave it a try. I've been trying to figure out what the problem with my code is for the entire day without success. I was wondering if someone could tell me what is my mistake. It is a very simple problem, four vertices, four edges, the result from the algorithm should be two: 2--------1 | | | | | | 0--------3 Source is 0, target is 1, all edges have unit capacity. The code is: void compute_max_flow(Graph* g_) { // obtain number of vertices in undirected graph size_t n = num_vertices(*g_); typedef adjacency_list_traits<vecS, vecS, directedS> Traits; typedef adjacency_list<listS, vecS, directedS, property<vertex_index_t, int>, property<edge_capacity_t, int, property<edge_residual_capacity_t, int, property<edge_reverse_t, Traits::edge_descriptor> > > > FlowGraph; typedef graph_traits<FlowGraph>::edge_descriptor EdgeFlow; FlowGraph g(num_vertices(*this->g_)); property_map<FlowGraph, vertex_index_t>::type indexmap = get(vertex_index, g); property_map<FlowGraph, edge_capacity_t>::type capacity = get(edge_capacity, g); property_map<FlowGraph, edge_reverse_t>::type rev = get(edge_reverse, g); property_map<FlowGraph, edge_residual_capacity_t>::type residual_capacity = get(edge_residual_capacity, g); Traits::vertex_descriptor s, t; EdgeFlow e1,e2; bool in1,in2; // add edges, reverse edges and capacities to new graph for flow computation edge_iter ei,ei_end; for (tie(ei,ei_end) = edges(*g_); ei != ei_end; ++ei) { // obtain vertices in the original graph vertex u = source(*ei, *g_); vertex v = target(*ei, *g_); // insert edges in new graph and add unit capacities tie(e1, in1) = add_edge(u,v,g); tie(e2, in2) = add_edge(v,u,g); if(in1 && in2) { // assign reverse edges to property map rev[e1] = e2; rev[e2] = e1; capacity[e1] = 1; capacity[e2] = 0; } } graph_traits<FlowGraph>::vertex_iterator vvi,vvi_end; for(tie(vvi,vvi_end) = vertices(g); vvi!=vvi_end; ++vvi) { cout<<"index -> "<<indexmap[*vvi]<<endl; } graph_traits<FlowGraph>::edge_iterator eei,eei_end; for(tie(eei,eei_end) = edges(g); eei!=eei_end; ++eei) { cout<<"edge -> "<<*eei<<endl; cout<<"capacity -> "<<capacity[*eei]<<endl; cout<<"rev -> "<<rev[*eei]<<endl; } int flow = push_relabel_max_flow(g, 0, 1, capacity, residual_capacity, rev, indexmap); cout<<"flow -> "<<flow<<endl; } Results in: index -> 0 index -> 1 index -> 2 index -> 3 edge -> (0,2) capacity -> 1 rev -> (2,0) edge -> (0,3) capacity -> 1 rev -> (3,0) edge -> (1,2) capacity -> 1 rev -> (2,1) edge -> (1,3) capacity -> 1 rev -> (3,1) edge -> (2,0) capacity -> 0 rev -> (0,2) edge -> (2,1) capacity -> 0 rev -> (1,2) edge -> (3,0) capacity -> 0 rev -> (0,3) edge -> (3,1) capacity -> 0 rev -> (1,3) flow -> 0 I would appreciate any inputs on this. Thank you, a²

2 5

Usage of Transitive_closure().
by Ning Ruan 10 Oct '07

10 Oct '07

my code to use transitive_closure(): Graph tc; VertexIndexMap index_map = get(&VertexProp::id, g); vector<Vertex> to_tc_vec(num_vertices(g)); iterator_property_map<Vertex*, VertexIndexMap, Vertex, Vertex&> g_to_tc_map(&to_tc_vec[0], index_map); transitive_closure(graph, tc, g_to_tc_map, (index_map)); I use print_graph(tc, get(&VertexProp::id, tc) to print the transitive graph, then it shows: 0 --> 0 0 0 0 0 0 0 0 0 --> 0 0 0 --> 0 --> 0 0 0 0 0 0 0 0 0 --> 0 --> 0 --> 0 0 0 0 --> 0 0 0 0 0 0 0 0 the result miss the id of vertex, what 's the problem. my original graph g is correcet: 0 --> 1 2 3 1 --> 4 5 2 --> 3 --> 6 7 4 --> 5 --> 6 --> 1 7 --> 0

3 4

regex_search in std::string
by Troy Alexander 10 Oct '07

10 Oct '07

I am struggling with a regex in some code of mine. I want to use regex_search to look for a match in a std::string, but my code will not build. This is a snippet of what I am trying to do. using namespace std; string in_file_name_s; string date_and_time_s; string day_s; char input_line[5000]; boost::regex re_date_time("(.*-.*-.*:.*:.*),.*,.*,.*,.*,.*,.*,.*,.*,"); boost::regex re_pices_date_time("(.*)\\-(.*)\\-(.*) (.*)"); boost::cmatch match; while (inFile.getline(input_line , 5000)) { if (boost::regex_search(input_line, match , re_date_time )) { date_and_time_s = match[1]; if (boost::regex_search(date_and_time_s , match , re_pices_date_time )) { day_s = match[1]; } } } When I compile I get the following error error C2784: 'bool boost::regex_search(const std::basic_string<charT,ST,SA> &,const boost::basic_regex<charT,traits> &,boost::regex_constants::match_flag_type)' : could not deduce template argument for 'const boost::basic_regex<charT,traits> &' from 'boost::cmatch' The 1st regex_search looking at input_line char[] works Ok it's the 2nd one looking at date_and_time_s std::string that gets the error. If I remark out the 2nd one the program builds and I watch the input_line doing what it should in the debugger. Also this code used to work before I upgraded from Visual C++6 to Visual C++8 and from bost_1_33_1 to boost_1_34_0. I don't know if it was the change in compiler or the boost lib that broke this. Thanks in advance for your help. Troy

2 1

Re: [Boost-users] Boost::regex causes runtime errors with CLR
by Hansi Hansi 10 Oct '07

10 Oct '07

Hello, In VS2005 is a problem with the Initializing of the CRT when you have a .net application. Normally it helps when you use as entry point '?mainCRTStartupStrArray@@$$FYMHP$01AP$AAVString@System@@@Z'. I hope this helps. Best regards Hansjörg _____________________________________________________________________ Der WEB.DE SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! http://smartsurfer.web.de/?mc=100071&distributionid=000000000066

2 1

Boost::regex causes runtime errors with CLR
by Rajib 09 Oct '07

09 Oct '07

Hi, I'm trying to use boost::regex with a "Windows Forms Application" in Visual Studio 2005. Everything works fine with normal C++, and even using a "CLR Console Application." But when I use the "Windows Form Application" template the program crashes while initializing variables. Basically I take code like: #include <boost/regex.hpp> using boost::regex; using boost::regex_search; bool h() { return regex_search("asdfasdf",regex("sd")); } put it in a separate file, turn off precompiled headers for that file, and never actually call h(). The program crashes instantly with a debug assertion failed at dbgheap.c/Line 1414/_CrtIsValidHeapPointer. The call stack looks like: ... msvcr80d.dll!__dllonexit(int (void)* func=0x00446110, void (void)* * * pbegin=0x0012eab8, void (void)* * * pend=0x0012eab0) Line 273 + 0x11 bytes C temp.exe!_onexit(int (void)* func=0x00446110) Line 110 + 0x11 bytes C temp.exe!atexit(void (void)* func=0x00446110) Line 127 + 0x9 bytes C temp.exe!boost::re_detail::`dynamic initializer for 'block_cache''() Line 189 + 0x2b bytes C++ ... It does this whether I compile the file with regex with the /clr flag or not (although the /clr flag gives a lot of errors, one of which isn't about converting fastcall to stdcall: include\boost/shared_ptr.hpp(92) : warning C4793: 'vararg' : causes native code generation for function 'void boost::detail::sp_enable_shared_from_this(const boost::detail::shared_count &,...)' Thanks, Rajib

1 0

Boost Spirit and C++/CLI
by Jason Stewart 09 Oct '07

09 Oct '07

Has anyone tried using boost spirit with C++/CLI? I have a library that uses Spirit internally to parse a file. The library is built as an unmanaged C++ static library. I then link that to a managed C++/CLI application but when I try to parse the file I get heap corruption. The corruption seems to happen near an #ifdef for BOOST_SPIRIT_THREADSAFE so I tried to define that for the build of the library and the application. Unfortunately it now fails to initialize correctly and dies on startup. Has anyone done this before? Thanks, Jason Stewart

1 0

boost::serialization XSD support
by Juhasz, Zoltan (IT) 09 Oct '07

09 Oct '07

Hi, I've got a pretty strange problem. We are using boost::serialization library to serialize arbitrary structs into XML. That is working pretty good. Our problems are: - we also need to generate schema files (XSD) for the archive file, since this XML archive file is going to be used by other programs (e.g. written in Java etc.), and - the unserialization part should be validated through the schema file. Currently, the boost::serialization library can serialize / deserialize our structs to XML just fine, but: How can we add XSD generation support? How can we 'force' boost::serialization to validate the XML file through an schema file (XSD)? PS: Unfortunately, the automatic generation of the XSD file is a strict requirement, that is why we cannot use regular XML <> C++ object mapping tools, where the C++ codes are generated by an external tool from a schema (XSD) file. PS2: If you know other third party tools that can solve the above mentioned problem, please feel free to write. Thank you in advance! Best Regards, Zoltan Juhasz Morgan Stanley | Technology | Budapest Zoltan dot Juhasz at MorganStanley dot com -------------------------------------------------------- NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error.

2 1

how to schedule nodes in graph
by Suresh Gupta 09 Oct '07

09 Oct '07

Hi, I want to do the following: I have a graph in boost. Now I want to schedule the graph nodes in topological order as follows: 1. The nodes which do not have any parents are to be scheduled in first cycle. Record the list of these nodes. 2. Remove already recorded nodes (in step 1) from the graph. 3. Repeat 1 and 2 on the remaining graph and so on. How to do the above? I need functions: 1. Get all nodes which do not have parents. 2. To remove the nodes from graph. Please suggest me about the functions in boost so do the same. Thanks, Suresh

2 3

Boost::Regex question
by Dima Kagan 09 Oct '07

09 Oct '07

Hi, I'm currently evaluating the Regex package and encountered a minor issue. I need to match a string that can contain some special characters (.[{()\*+?|^$) as well. My question is if there is a way to tell Regex to treat this string "as is", including the special characters? I need to do this without escaping the special characters in the string or the match expression. For those of you familiar with Tcl Expect, I'm looking for an option similar to "expect -ex". Thank you! Regards, Dima Kagan

2 2

defining a function according to a signature given as template parameter
by Stefan Funck 09 Oct '07

09 Oct '07

Hi everybody, I'd like to have a generic wrapper that can be put "in between" a signal and a slot to provide some additional functionality to the slot. So where I normally have something like void myslot(int i) { std::cout << "slot(" < sig; sig.connect(boost::bind(myslot, _1)); sig(123); return 0; } I want something like int main(int argc, char *argv[]) { boost::signal<void (int)> sig; SlotWrapper<void (int)> slotWrap(boost::bind(myslot, _1)); sig.connect(boost::bind(SlotWrapper<void (int)>::slot, &slotWrap, _1)); sig(123); return 0; } The signature of SlotWrapper<Signature>'s member function slot() is defined by Signature. slot()'s implementation should have some common functionality (that's what I want the wrapper for) and then call the actual slot that was given at construction (myslot() in the example above). Is that doable? So far I have two questions: 1) How can I define a member function according to the signature that is given as a template parameter to the class? 2) If I can do 1), how can I then bind the arguments given and call another function, i.e. the original slot? A skeleton of the wrapper might look like: template <typename Signature> class SlotWrapper { public: SlotWrapper(const typename boost::signal<Signature>::slot_function_type& slot) : m_slot(slot) {} // define a function according to Signature typename boost::signal<Signature>::result_type slot(...arguments...) { // do something common // call somehow the actual slot (m_slot) with the given ...arguments... } private: const typename boost::function<Signature> m_slot; }; How can I write the slot() function? Thanks for any help, Stefan

2 2

boost::basic_match::size_type
by Bill Webster 09 Oct '07

09 Oct '07

The basic_match access methods have int index parameters, whereas basic_match::size() returns basic_match::size_type. This means that the following results in compiler warnings (under MSVC 8.0) - boost::smatch match; // ... for ( boost::smatch::size_type i = 0; i < match.size(); i++ ) { cout << match.str( i ).c_str() << endl; }

1 0

Dimensional analysis
by Joel C. Salomon 09 Oct '07

09 Oct '07

Have the dimensional analysis templates suggested in <http://www.boost.org/libs/mpl/doc/tutorial/dimensional-analysis.html> ever been developed into readily usable form? --Joel

3 3

serialization and object tracking question...
by Graham Reitz 09 Oct '07

09 Oct '07

I am having trouble wrapping my head around object tracking for serialization. I see how to change the default behavior: BOOST_CLASS_TRACKING(my_class, boost::serialization::track_never) ...but based on the error below how do I determine what kind of object tracking is needed? oserializer.hpp:566: error: invalid application of 'sizeof' to incomplete type 'boost::STATIC_ASSERTION_FAILURE<false>' inline void save(Archive & ar, T &t){ // if your program traps here, it indicates taht your doing one of the following: // a) serializing an object of a type marked "track_never" through a pointer. // b) saving an non-const object of a type not markd "track_never) // Either of these conditions may be an indicator of an error usage of the // serialization library and should be double checked. See documentation on // object tracking. BOOST_STATIC_ASSERT(check_tracking<T>::value); The following is the class to be serialized: class client_i { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & m_client; } clients m_client; public: client_i() {}; client_i(clients c) : m_client(c) {}; ~client_i() {}; }; clients is a mysql++ specialized sql structure that is created via one of the mysql++ macros, i.e. sql_create_N(). Any help understanding this would be greatly appreciated. Thanks, Graham

2 4

thread creating just hangs
by Eyon Land 08 Oct '07

08 Oct '07

Hey folks, I'm new to boost. I've used pthread and wanted to try out boost::thread. After installing the latest release I found that creation of the thread instance simply hangs. I use CentOS 4.3 on a single CPU machine. Has this happened to anyone else? Thanks in advance! Eyon ____________________________________________________________________________________ Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games. http://sims.yahoo.com/

1 0

Threads, condition variables, and signals
by Scott Gifford 08 Oct '07

08 Oct '07

Hello, I'm writing a multithreaded server on Unix using boost::thread. The basic operation is fairly straightforward; a master thread starts up worker threads, and coordinates various management tasks using condition variables. As with most Unix servers, the server is shut down with an OS signal telling the server to shut down. The server catches this signal, then simply calls exit(1). Any important cleanup happens in the destructors of global variables, so it will happen properly no matter how the server exits. One object which is always cleaned up is the object for the master thread. The master thread sets a flag, then does a notify_all() on some condition variables to tell the other threads to shut down, The problem I'm having is that if the master thread is waiting on a condition variable when the signal arrives, and the destructor does a notify_all() on that condition variable, then the destructor for the boost::condition variable hangs. For example, if I run the included code and hit CTRL-C after a short bit, I get this output: Waiting... ^C Caught signal 2 Destroyed ThreadTest Running destructor 1 [ ... hangs ... ] Here is the program: #include <iostream> #include <signal.h> #include <boost/thread.hpp> #include <boost/thread/mutex.hpp> #include <boost/thread/condition.hpp> template<int n> struct PrintOnDestruct { ~PrintOnDestruct() { std::cout << "Running destructor " << n<< std::endl; } }; class ThreadTest { public: void doSomething() { boost::mutex::scoped_lock lock(myMutex); while(true) { std::cout << "Waiting..." << std::endl; myCond.wait(lock); } } ~ThreadTest() { boost::mutex::scoped_lock lock(myMutex); myCond.notify_all(); std::cout << "Destroyed ThreadTest" << std::endl; } private: PrintOnDestruct<2> d2; boost::mutex myMutex; boost::condition myCond; PrintOnDestruct<1> d1; }; // Exit properly on signal void sighandle(int sig) { std::cerr << "Caught signal " << sig << std::endl; exit(1); } ThreadTest tt; int main() { // Get ready to handle signals signal(SIGINT,sighandle); tt.doSomething(); } Does anybody have any suggestions for a straightforward way to handle this properly? Thanks! ----ScottG.

2 3

[preprocessor] using __FILE__ with BOOST_PP_FILENAME_x
by Server Levent Yilmaz 08 Oct '07

08 Oct '07

Hi all, Please take a look as this trivial example of file iteration: // trivial.h #if !BOOST_PP_IS_ITERATING #ifndef TRIVIAL_H #define TRIVIAL_H #include <boost/preprocessor/iteration/iterate.hpp> #define BOOST_PP_FILENAME_1 "trivial.h" //!!! #define BOOST_PP_ITERATION_LIMITS (1, 3) ??=include BOOST_PP_ITERATE() #endif // TRIVIAL_H #else BOOST_PP_ITERATION() #endif Perhaps not so obvious many (wasn't to me), that #define BOOST_PP_FILENAME_1 __FILE__ doesn't work. One has to specify (kind of like hardcode) the file's name in there.. Is there some, possibly contrived, way to achieve automation of this? regards, - Levent PS: What an AMAZING library this Boost.Preprocessor is!? -- Server Levent Yilmaz Mechanical Engineering University of Pittsburgh

2 2

exp functions with interval
by Mark Beinker 08 Oct '07

08 Oct '07

Hi, I was trying to use the boost interval class using g++ under cygwin and ubuntu, but unfortunately, I have trouble to use the exp function. The following code: #include <iostream> #include <cmath> #include <boost/numeric/interval.hpp> #define DOUBLE boost::numeric::interval<double> int main(int argc, char** argv) { DOUBLE x(4,5); std::cout.precision(19); DOUBLE res = exp(x); std::cout<<'['<<res.lower()<<", "<<res.upper()<<']'<<std::endl; return 0; } generates the following compile error: /usr/include/boost/numeric/interval/transc.hpp: In function `boost::numeric::interval<T, Policies> boost::numeric::exp(const boost::numeric::interval<T, Policies>&) [with T = double, Policies = boost::numeric::interval_lib::policies<boost::numeric::interval_lib::rounded_math<double>, boost::numeric::interval_lib::checking_strict<double> >]': itest.cpp:14: instantiated from here /usr/include/boost/numeric/interval/transc.hpp:34: error: 'struct boost::numeric::interval_lib::rounded_math<double>' has no member named 'exp_down' itest.cpp:14: instantiated from here /usr/include/boost/numeric/interval/transc.hpp:34: error: 'struct boost::numeric::interval_lib::rounded_math<double>' has no member named 'exp_up' I use boost version 1.34.1. Any idea why this doesn't work? Regards, Mark

2 1

[string_algo] Case-insensitive keys in map with is_iless?
by Boris 07 Oct '07

07 Oct '07

Am I supposed to be able to use boost::algorithm::is_iless (see http://www.boost.org/doc/html/boost/algorithm/is_iless.html) to create a map with case-insensitive keys? I wonder as either it is broken in VS2005 or I do something wrong: #include <boost/algorithm/string.hpp> #include <string> #include <map> int main() { std::map<std::string, int, boost::algorithm::is_iless> m; m["test"] = 1; } C:\Program Files\Microsoft Visual Studio 8\VC\include\xlocale(583) : error C2440: 'type cast' : cannot convert from 'unsigned char' to 'std::basic_string<_Elem,_Traits,_Ax>' ... C:\Program Files\Microsoft Visual Studio 8\VC\include\xlocale(561) : error C2440: 'type cast' : cannot convert from 'std::basic_string<_Elem,_Traits,_Ax>' to 'unsigned char' The assignment causes the problem. If you use insert() you get the same compiler error. Without the assignment the code compiles fine. Boris

2 3

"Missing" lib for 1_34_1 using MSVC-71
by Larry 07 Oct '07

07 Oct '07

I had a program that I had built with Boost 1_34 and it worked well (built with MSVC 7.1). I downloaded 1_34_1 and built 1_34_1 for VC8 and VC7.1 using bjam 3.1.14. bjam --toolset=msvc-7.1 install I switched the program build to use Boost 1_34_1 and the build fails looking for libboost_date_time-vc71-mt-sgd-1_34_1.lib as part of the link. Going back to the Boost build I find msvc.archive bin.v2\libs\date_time\build\msvc-71\debug\link-static\runtime-link-static\libboost_date_time-vc-sgd-1_34_1.lib common.copy C:\Boost\lib\libboost_date_time-vc-sgd-1_34_1.lib 1 file(s) copied. The only thing I changed was the include list entry from c:\boost\include\boost_1_34 to c:\boost\include\boost_1_34_1. The lib directory is the same in both cases. I didn't find anything looking through the boost.user group or in the doc but perhaps I looked at it and just didn't realize the answer was there. Perhaps I didn't do something I should have or did something I shouldn't have. Any ideas? I got surprised (probably again) when building Boost because I had run vcvars32.bat for MSVC 7.1 and then did bjam --toolset=msvc install and the surprise was it built for MSVC 8.0. The doc does say the build will find the VC compiler but I had sort of assumed it would use what was in the environment before searching elsewhere for a compiler version. But after that I ran bjam --toolset=msvc-71 install and it ran without complaint. I did several iterations of the 7.1 build including a build with -a and also did a --clean followed by a Boost build and neither altered the outcome of the Boost build (that I could see) and did not alter the outcome of the program build with VC 7.1. The program build was done via VS. Moving the include back to 1_34 works. Larry

2 2

[thread] example to delegtate jobs to threads
by Torsten Mohr 07 Oct '07

07 Oct '07

Hi, i wrote a small test project that makes use of boost::thread to split jobs into parts that are delegated to threads. A class "Job" contains a state machine (IDLE, EXECUTING, ABORTED, ...). That class can be derived from and methods "execute" and "report" can be overwritten. A class JobProvider can be derived from to feed new data to a Job. A Template "Foreman" can then start several threads and delegate Jobs that get their data from "JobProvider" to the Jobs and they report when they are done. In the example, MyJobProvider provides numbers from 3 to 100. MyJob::execute calculates if these numbers are prime. MyJob::report prints out the numbers that are prime. All the methods "report" are protected, only one of them at a time is ever called, methods "execute" are run in parallel. The performance is poor, can anybody give me a hint why? Best regards, Torsten. ######## job.h: #ifndef JOB_H #define JOB_H 1 #include <boost/thread.hpp> extern boost::mutex io_mutex; #define QWE { boost::mutex::scoped_lock lck(io_mutex); printf("file %s line %i\n", __FILE__, __LINE__); } class Job { boost::mutex job_mutex; boost::mutex cond_mutex; boost::mutex* m_report_mutex; boost::condition* m_condition; boost::thread* thr; bool m_stopped; int m_state; void setState(int state); protected: bool is_stopped(void); public: enum { CMD_IDLE = 212, CMD_EXEC, CMD_KILL }; enum { STATE_IDLE = 37, STATE_EXEC_PREPARE, STATE_EXEC, STATE_EXEC_ABORTED, STATE_REPORT_PREPARE, STATE_REPORT, STATE_DEAD }; void set_foreman_data(boost::mutex* report_mutex, boost::condition* condition); void init(void); virtual void execute_handler(void); void report_handler(void); void fork(void); int getState(void); void doCommand(int command); virtual void execute(void); virtual void report(void); }; class JobProvider { public: bool provide(Job& j); }; #endif ######## job.cc: #include <boost/thread.hpp> #include <boost/bind.hpp> #include "job.h" int Job::getState(void) { boost::mutex::scoped_lock lock(job_mutex); return m_state; } void Job::setState(int state) { boost::mutex::scoped_lock lock(job_mutex); m_state = state; } void Job::doCommand(int cmd) { boost::mutex::scoped_lock lock(job_mutex); // sparse transitions if((m_state == STATE_EXEC || m_state == STATE_EXEC_PREPARE) && cmd == CMD_KILL) { m_state = STATE_EXEC_ABORTED; m_stopped = true; } else if(m_state == STATE_IDLE && cmd == CMD_EXEC) { m_state = STATE_EXEC_PREPARE; } else if(m_state == STATE_IDLE && cmd == CMD_KILL) { m_state = STATE_DEAD; m_stopped = true; } } bool Job::is_stopped(void) { boost::mutex::scoped_lock lock(job_mutex); return m_stopped; } void Job::execute_handler(void) { int state; do { state = getState(); switch(state) { case STATE_EXEC_PREPARE: execute(); state = getState(); if(state != STATE_EXEC_ABORTED) { boost::mutex::scoped_lock lock(*m_report_mutex); report(); m_condition->notify_one(); setState(STATE_IDLE); } break; case STATE_DEAD: case STATE_EXEC_ABORTED: return; } } while(1); } void Job::init(void) { m_state = STATE_IDLE; } void Job::fork(void) { thr = new boost::thread(boost::bind(execute_handler, this)); } void Job::report_handler(void) { boost::mutex::scoped_lock lock(*m_report_mutex); report(); } void Job::set_foreman_data(boost::mutex* report_mutex, boost::condition* condition) { m_report_mutex = report_mutex; m_condition = condition; } void Job::execute(void) { } void Job::report(void) { } ######## foreman.h: #ifndef FOREMAN_H #define FOREMAN_H 1 #include <boost/thread.hpp> #include <boost/bind.hpp> #include "job.h" template<class JOBB, class JOBB_PROVIDER> class Foreman { JOBB* jb; JOBB_PROVIDER* m_provider; int m_threads; bool m_finished; boost::mutex report_mutex; boost::mutex m_cond_mutex; boost::condition m_condition; boost::thread* me; void handler(void); public: Foreman(int threads, JOBB_PROVIDER* provider); ~Foreman(); void spawn(void); void cleanup(void); void abort(void); bool is_finished(void); }; template<class JOBB, class JOBB_PROVIDER> Foreman<JOBB, JOBB_PROVIDER>::Foreman(int threads, JOBB_PROVIDER* provider) : m_threads(threads), m_provider(provider) { jb = new JOBB[m_threads]; } template<class JOBB, class JOBB_PROVIDER> Foreman<JOBB, JOBB_PROVIDER>::~Foreman() { delete[] jb; } template<class JOBB, class JOBB_PROVIDER> void Foreman<JOBB, JOBB_PROVIDER>::handler(void) { bool all_done; do { boost::mutex::scoped_lock lock(m_cond_mutex); all_done = true; for(int i = 0; i < m_threads; ++i) { int state = jb[i].getState(); if(state == Job::STATE_IDLE) { if(m_provider->provide(jb[i])) { jb[i].doCommand(Job::CMD_EXEC); all_done = false; } else { m_finished = true; } } else { all_done = false; } } if(m_finished || all_done) { return; } m_condition.wait(lock); } while(1); // (!m_finished || !all_done); } template<class JOBB, class JOBB_PROVIDER> void Foreman<JOBB, JOBB_PROVIDER>::spawn(void) { for(int i = 0; i < m_threads; ++i) { jb[i].set_foreman_data(&report_mutex, &m_condition); jb[i].init(); jb[i].fork(); } m_finished = false; // me = new boost::thread(boost::bind(handler, this)); handler(); } template<class JOBB, class JOBB_PROVIDER> void Foreman<JOBB, JOBB_PROVIDER>::cleanup(void) { // me->join(); } template<class JOBB, class JOBB_PROVIDER> void Foreman<JOBB, JOBB_PROVIDER>::abort(void) { } template<class JOBB, class JOBB_PROVIDER> bool Foreman<JOBB, JOBB_PROVIDER>::is_finished(void) { return m_finished; } #endif ######## my_job.h: #ifndef MY_JOB_H #define MY_JOB_H 1 #include "job.h" class MyJob : public Job { int m_suspect; bool is_prime; public: MyJob(); virtual void execute(void); virtual void report(void); void setJobStuff(int suspect); }; class MyJobProvider : public JobProvider { int m_actual; public: MyJobProvider(); bool provide(MyJob& j); }; #endif ######## my_job.cc: #include <iostream> #include <math.h> #include "my_job.h" #include "job.h" MyJob::MyJob() { m_suspect = 0; } void MyJob::setJobStuff(int suspect) { m_suspect = suspect; } void MyJob::execute(void) { int root = (int)sqrt((double)m_suspect); for(int j = 2; j <= root; j++) { if(is_stopped()) { return; } if((m_suspect % j) == 0) { is_prime = false; return; } } is_prime = true; } void MyJob::report(void) { if(is_prime) { std::cout << m_suspect << " is prime" << std::endl; } } MyJobProvider::MyJobProvider() : m_actual(3) {} #define NN 100 bool MyJobProvider::provide(MyJob& j) { j.setJobStuff(m_actual); m_actual++; if(m_actual > NN) return false; return true; } ######## qwe.cc: #include <iostream> #include "job.h" #include "my_job.h" #include "foreman.h" boost::mutex io_mutex; void test1(void) { MyJobProvider p; MyJob j; while(p.provide(j)) { j.execute(); j.report(); } } void test2(void) { MyJobProvider p; Foreman<MyJob, MyJobProvider> fm(7, &p); fm.spawn(); do { } while(!fm.is_finished()); fm.cleanup(); } int main(int argc, char** argv) { test2(); return 0; }

1 0

Serializing a Method
by at forum 07 Oct '07

07 Oct '07

Hi to all I am new to the boost library, I downloaded it and I am doing some tests. I was using MFC serialization. I want to do something like this : template<class _CReceiver, class _CMemberType> class CASetMemberCommand { friend class boost::serialization::access; public: typedef void (_CReceiver::* Action)(_CMemberType) ; protected: _CReceiver *m_pReceiver; _CMemberType m_Property; Action m_fnAction; public: CASetMemberCommand() { m_pReceiver = NULL; } CASetMemberCommand(_CReceiver *pReceiver, Action fnAction, _CMemberType memberProperty) { m_pReceiver = pReceiver; m_fnAction = fnAction; m_Property = memberProperty; } ~CASetMemberCommand() { } virtual void Execute() { if(m_pReceiver) (m_pReceiver->*m_fnAction)(m_Property); } template<class Archive> void serialize(Archive & ar, const unsigned int /* file_version */){ ar & BOOST_SERIALIZATION_NVP(m_pReceiver) //& BOOST_SERIALIZATION_NVP(m_fnAction) & BOOST_SERIALIZATION_NVP(m_Property); } void Save(const char * filename) { std::ofstream ofs(filename); assert(ofs.good()); boost::archive::xml_oarchive oa(ofs); oa << BOOST_SERIALIZATION_NVP(this); } void Load( const char * filename) { std::ifstream ifs(filename); assert(ifs.good()); boost::archive::xml_iarchive ia(ifs); ia >> BOOST_SERIALIZATION_NVP(*this); } }; int main(int argc, char *argv[]) { gps_position pos(32,52,25.0f); CASetMemberCommand<gps_position,int> cmd(&pos,&gps_position::SetMinutes,25); CASetMemberCommand<gps_position,int> cmd4(&pos,&gps_position::SetDegrees,25); cmd.Execute(); SaveCommand(cmd,"D:/test.xml"); cmd.Save("D:/Test2.xml"); CASetMemberCommand<gps_position,int> cmd2; cmd2.Load("D:/Test2.xml"); return 0; } the problem is that BOOST_SERIALIZATION_NVP(m_fnAction) is not working (compile errors); Is there any way to save a methode of w class, so it can be loaded and used later? Thank you

2 3

Allocator and smart_ptrs
by Seweryn Habdank-Wojewódzki 06 Oct '07

06 Oct '07

Dears I found that only shared_ptr can use allocator. Is there any possibility to join the existing allocator and the other smart_ptrs. Why the rest smart_ptrs can not use allocators? Regards. -- |\/\/| Seweryn Habdank-Wojewódzki \/\/

2 4

Need a help about boost.thread
by Steven Woody 06 Oct '07

06 Oct '07

hi, i am doing a job and considering if boost.thread can help. what i am doing is writing some code for other one's use. my code will be called by many threads, and accessing some shared data. my problem is how to keep my code thread-safe. i have no way to control how those other threads were created ( actually, those had already done by another team using windows MFC, and, for some reasons, my code can not use MFC, is has to be portable bwteen Linux and Windows ). in breif, you can think my code in a way of producer/consumer pattern. the producer is a rouine which will be called by many threads ( which are actaully connected sockets created by a listening socket ), and the consumer routine will be called by another thread ( which is actually GUI's main thread ). what i expected is: 1, only one producer can write to the shared data; 2, when a producer is writting, other producers have to busy waiting; and the GUI thread should immediately exit; 3, when GUI thread is reading, no producer can write to the shared data; to my problem, does the boost.thread can help? thanks in advance. -- woody then sun rose thinly from the sea and the old man could see the other boats, low on the water and well in toward the shore, spread out across the current.

3 7

Boost/C++ group on facebook
by Jan Stetka 06 Oct '07

06 Oct '07

Boost/C++ group on facebook: Already have 47 members! Show your support for boost (unofficially) http://www.facebook.com/group.php?gid=4200526117

2 2

boost bindings
by e r 06 Oct '07

06 Oct '07

i, i looked at previous posts on this topic. did not help, a suggestion would be appreciated: installed atlas version 3.6.0-20.6 /usr/lib/atlas3-test runs just fine. header cblas.h and clapack.h are in /usr/include/ which is by default in my include path. Configuration: -I/usr/local/include/boost_1_34_1 -I/usr/local/include/boost-bindings -L/usr/lib/atlas -llapack -lblas i'm trying to run the program: #include <boost/numeric/bindings/atlas/clapack.hpp> #include <boost/numeric/bindings/traits/ublas_matrix.hpp> #include <boost/numeric/bindings/traits/std_vector.hpp> // #include <atlas/cblas.h> namespace ublas = boost::numeric::ublas; namespace atlas = boost::numeric::bindings::atlas; int main() { std::size_t n = 5; ublas::matrix<double> a(n, n); // fill matrix a std::vector<int> ipiv (n); // pivot vector atlas::lu_factor (a, ipiv); // alias for getrf() atlas::lu_invert (a, ipiv); // alias for getri() return 0; }; i get the error Building target: testing_numeric_bindings Invoking: GCC C++ Linker g++ -L/usr/lib/atlas -o"testing_numeric_bindings" ./main.o -llapack -lblas ./main.o: In function `boost::numeric::bindings::atlas::detail::getrf(CBLAS_ORDER, int, int, double*, int, int*)': /usr/local/include/boost-bindings/boost/numeric/bindings/atlas/clapack_overloads.hpp:87: undefined reference to `clapack_dgetrf' ./main.o: In function `boost::numeric::bindings::atlas::detail::getri(CBLAS_ORDER, int, double*, int, int const*)': /usr/local/include/boost-bindings/boost/numeric/bindings/atlas/clapack_overloads.hpp:163: undefined reference to `clapack_dgetri' collect2: ld returned 1 exit status make: *** [testing_numeric_bindings] Error 1 make: Target `all' not remade because of errors. Build complete for project testing_numeric_bindings

2 3

ublas/matrix product/efficiently compute A * B * C
by e r 05 Oct '07

05 Oct '07

currently i do: boost_auxiliary::matrix_double D; boost::numeric::ublas::axpy_prod(A, B, D, true); boost::numeric::ublas::axpy_prod(D, C, D, true); there must be a better way? A * B * C generates an ambiguous overloaded operator* message (ambiguous with element-wise product, i read). pls help.

1 0

[interprocess] - Usage of boost::interprocess::open_or_create mode
by Srinivas Gardas 05 Oct '07

05 Oct '07

Hi, I am quite new to boost. Are there any code examples around usage of 'open_or_create' mode for ceating the shared_memory_object? My problem is, after we create a 'shared_memory_object' using 'open_or_create' there is no way to know whether it created 'created' a file or 'opened' an already existing file. We need this apparently, because if we are creating a new file, we have to '*construct<container>("MySharedMemory") *' the file with the desired container, otherwise we have to '* find<container>("MySharedMemory")*'. All the usage examples I could get were only around 'create_only' and then 'open_only' modes.. My idea is to write one single method, that'd use the 'open_or_create' mode so that we don't have to bother.. a sequence of creation and then usage.. I am not sure if I was clear enough in putting my problem across, please feel free to respond with questions. Really appreciate any help around this. Thanks & Regards, Srinivas Gardas

2 1

[random] getting a 50% probability generator
by Jeffrey Holle 05 Oct '07

05 Oct '07

I am at the point in my application where I must introduce randomness to a sort routine. Basically when 2 elements are equal, I need to create a 50% probability that they will be swapped. What is the correct boost::random library resource to code this? I've attempted to use uniform_01, by creating an instance of it with this type: typedef boost::uniform_01<boost::minstd_rand, double> rand_gen_t; However, after getting it constructed as a class attribute, I find accessing it with: cout << (*pRand_gen++) << endl; It produces numbers like 1 134784888 134784288 2 134784845 134784224 134785176 5 0 134784376 134785328 0. What I want is a sequence like 0 1 0 1 0 1 0 0 0 1 1 1 1 0 1 0 1 that is sort of random.

4 5

[boost-users] enable_if on boost::operators compile error on visual c++.
by chun ping wang 05 Oct '07

05 Oct '07

Given this code which is suggested by David Abraham.... template <class T, class U> char (& is_op_test(boost::operators<T,U> const&) )[2]; template <class T> char is_op_test(T const&); template<class T> T const& make(); template <class T> struct is_operators : boost::mpl::bool_<(sizeof(is_op_test(make<T>())) == 2)> {}; and this function declaration. template <typename T, template <typename ELEM, typename = std::allocator<ELEM> > class CONT > typename boost::enable_if<boost::mpl::or_<boost::is_integral<T>, boost::is_operators<T> >, CONT<T> >::type primelist(const T& MAX_BOUND, const T& K, boost::function<bool(const T&, const T&)> f); I compile with T = int and it works. When i compile with T = BigInteger I get the following errors. ./cs512/c++/primeMain.cpp(78) : error C2770: invalid explicit template argument(s) for 'boost::enable_if<boost::mpl::or_<boost::is_integral<T>,boost::is_operators<T> >,CONT<T>>::type primelist(const T &,const T &,boost::function<bool(const T &,const T &)>)' ./cs512/c++/primeMain.cpp(24) : see declaration of 'primelist'" BigInteger class declaration looks like this.. class BigInteger : public BigUnsigned, boost::operators<BigInteger>, boost::operators<BigInteger, int> { }; thanks for the help.

1 0

lexical_cast
by Peter Sliepenbeek 05 Oct '07

05 Oct '07

Hi all, The test below fails: #include <iostream> #include <boost/lexical_cast.hpp> int main(int argc, char* argv[]) { std::string s; try { double d = std::numeric_limits <double> ::max(); s = boost::lexical_cast <std::string> (d); } catch (const boost::bad_lexical_cast&) { std::cout << "double to std::string fails" << std::endl; } try { double dd = boost::lexical_cast <double> (s); } catch (const boost::bad_lexical_cast&) { std::cout << "std::string to double fails" << std::endl; } return 0; } To solve this issue I propose to alter the line "stream.precision(std::numeric_limits<Target>::digits10 + 1" in the constructor for lexical_stream into "stream.precision(std::numeric_limits<Target>::digits10 - 1". Regards, P. Sliepenbeek --------------------------------- Be a better Heartthrob. Get better relationship answers from someone who knows. Yahoo! Answers - Check it out.

2 1

[Boost.FileSystem] File or Wildcards in Path? How-to do this?
by Lawrence Spector 05 Oct '07

05 Oct '07

Here's a simple example. Is there a way to do achieve this effect? std::string folderName = "C:\\*.sys"; boost::filesystem::path fsDirectoryPath = boost::filesystem::system_complete( boost::filesystem::path(folderName, boost::filesystem::native)); boost::filesystem::directory_iterator end_iter; for (boost::filesystem::directory_iterator dir_itr(fsDirectoryPath); dir_itr != end_iter; ++dir_itr) // throws exception { std::cout << "Contains the following file: " << dir_itr->string() << std::endl; } // end for When I do this, I get the following exception: boost::filesystem::basic_directory_iterator constructor I don't see any documentation for how to narrow your searches with wildcards or how to only find files that match a particular file name. Am I missing something? Obviously you can refine your search later in the loop, but that is inefficient. Please let me know. Thanks, Lawrence

3 6

A tuple performance question
by Peng Yu 05 Oct '07

05 Oct '07

Hi, It is mentioned at http://www.boost.org/libs/tuple/doc/tuple_users_guide.html#performance that the following two ways would be different in term of performance. ////////////// void f1(int&, double&); tuple<int, double> f2(); //Then, the call #1 may be slightly faster than #2 in the code below: int i; double d; ... f1(i,d); // #1 tie(i,d) = f2(); // #2 /////////////////// What about the current commonly used compiler, such as GCC? Are #1 and #2 different in GCC? Does the compiler always have some way to optimize #2 to make it as good as #1? Is it just a matter of fact whether the optimization method is implemented? Or #2 can never be made as good as #1? Thanks, Peng

7 15

Any way to work around missing <locale> under Windows CE ?
by luper rouch 05 Oct '07

05 Oct '07

The standard <locale> include file is not shipped with the windows CE/mobile sdks, and therefore lots of boost parts are unusable. Is there a way to work around this problem in boost ? Luper Rouch

4 3

[interprocess]failed to build doc
by Sean Huang 05 Oct '07

05 Oct '07

Has anybody had any success in building doc for interprocess (trunk version). Doxygen 1.5.3 crashed and I switched to 1.4.7 but I'm still getting the following errors: xslt-xsltproc .\..\..\bin.v2\libs\interprocess\doc\msvc-8.0\debug\threading-multi\autodoc -xml.boostbook warning: failed to load external entity "Reference" cannot parse Reference set XML_CATALOG_FILES=..\..\..\bin.v2/boostbook_catalog.xml "xsltproc.exe" --stringparam boost.doxygen.refid " "reference"" --stringparam boost.doxygen.reftitle ""Boost.Interprocess Reference"" --xinclude -o "..\..\..\bin.v2\libs\interprocess\doc\msvc-8.0\debug\threading-multi\autodo c-xml.boostbook" "boost\boost\tools\boostbook\xsl\doxygen\doxygen2boostbook.xsl" "..\..\..\bin.v2\libs\interprocess\doc\msvc-8.0\debug\threading-multi\autodo c-xml.doxygen" ..failed xslt-xsltproc .\..\..\bin.v2\libs\interprocess\doc\msvc-8.0\debug\threading-multi\autodoc -xml.boostbook... ..skipped <p.>autodoc.xml for lack of <p..\..\..\bin.v2\libs\interprocess\doc\msvc-8.0\debug\threading-multi>autod oc-xml.boostbook... ..skipped <p..\..\..\bin.v2\libs\interprocess\doc\msvc-8.0\debug\threading-multi>inter process.docbook for lack of <p.>a utodoc.xml... ..skipped <phtml>standalone_HTML.manifest for lack of <p..\..\..\bin.v2\libs\interprocess\doc\msvc-8.0\debug\threading- multi>interprocess.docbook... ..failed updating 1 target... ..skipped 3 targets... Thanks, Sean

2 2

Re: [Boost-users] follow up on regex questions
by Mike Marchywka 04 Oct '07

04 Oct '07

OK, I think my earlier concern about greta dropping data was incorrect as it was the result of hastily adapting a piece of code for testing- that wouldn't have occured before. I went back to verify that boost still gives the same results as greta with simpler regexes and still have identical results. Is there anything that "()" can do to the stack that could be causing flakey results? This fails on some data ( program hangs or seg faults): ATG(.)*?(TAG|TAA|TGA) >rule|2|DNA Euk ORF This works on data I have ( although I thought I saw it failing earlier, I have yet to see the 1000 other regex's fail in boost ): ATG.*?(TAG|TAA|TGA) >rule|2|DNA Euk ORF The working regex's do not have non-terminal "()"- while they may have "()" these are only at begin or end and include two choices, one of which is "^" or "|" ) My calling code looks something like this ( again, everything is char* ) while(regex_search(start, end, what, expression, flags)) { if (which>=what.size()) { es<<MM_MARK<<" which "<< which <<" vs size "<<what.size()<<'\n'; ; return -1; } int st=what[which].first - sample; int len=what[which].second-what[which].first; typedef VecTy::value_type Val; rv.push_back(Val(st,st+len )); start = what[which].second; // This makes things OVERLAP, may not be desired behavior. if ( rv.olap_group()) start = what[0].first+1; if ( rv.olap_which()) start = what[which].first+1; // update flags: flags |= boost::match_prev_avail; flags |= boost::match_not_bob; } Thanks again. >From: "John Maddock" <john(a)johnmaddock.co.uk> >Reply-To: boost-users(a)lists.boost.org >To: <boost-users(a)lists.boost.org> >Subject: Re: [Boost-users] follow up on regex questions >Date: Thu, 4 Oct 2007 17:37:22 +0100 > >Mike Marchywka wrote: > > Hi, > > Thanks for your help in the past. I would normally drop the issue at > > this point > > until I get my build environment cleaned up > > (" My build is messed up, I haven't read the documentation. What is > > wrong with YOUR library?" LOL). > > but I do have one more question which I believe is related to boost > > regex processing. > > If someone has a known good regex test program or can point to an > > obvious problem > > it may be helpful. > >You mean libs/regex/test/regress/*.cpp ? > >It would be a good idea to build and run this to verify the sanity of your >setup at least: I still have a suspision that the binaries you are using >are >not compatible with your build options or regex headers, but I can't be >sure. > > > Again, this code seems to work with Microsoft's > > greta and boost gives identical results on a longer list of SIMPLER > > regexes so I reasonably believe that the problem is due to handling > > of more complicated expression ( One caveat, to be complete, is that > > greta did seem to return some spurious > > results but they are easily filter programmatically, things like > > negative location, > > but the plausible ones that I have checked manually are right). > > However, on this sequence of regexes (regexi?) I get either an abort > > OR the program hangs > > later on non-sensical execution (I know, "Gee, you have a build > > problem and the stack is messed up?"). > > > > myboost.cpp114 (GU.*?TACTAAC.{20,40}AG|^)(.*?)(GU.*?TACTAAC.{20,40}AG) > > myboost.cpp114 ATG(...)*?(TAG|TAA|TGA) > > myboost.cpp114 TATAA.*?ATAAA > > myboost.cpp114 (GU.*?TACTAAC.{20,40}AG|^)(.*?)(GU.*?TACTAAC.{20,40}AG) > > myboost.cpp114 ATG(...)*?(TAG|TAA|TGA) > > > > ( progam hangs in my code or had been core dumping in boost::regex ) > >What is the text you are matching against? If you can give me a concrete >example I can test it here, but "it hangs" isn't very useful I'm afraid ;-) > >John. > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users _________________________________________________________________ Help yourself to FREE treats served up daily at the Messenger Café. Stop by today! http://www.cafemessenger.com/info/info_sweetstuff2.html?ocid=TXT_TAGHM_OctH…

1 0

[Iostreams] Issue with mapped_file
by JD 04 Oct '07

04 Oct '07

Hello, There is something I don't get with mapped_file from the IOStreams library. Here is an example: // Code snippet #include <iostream> #include <boost/iostreams/device/mapped_file.hpp> #include <boost/iostreams/stream.hpp> using namespace boost::iostreams; int main(int argc, char **argv) { if (argc != 2) return 1; try { stream <mapped_file_sink> out; mapped_file_params p(argv[1]); p.new_file_size = 1024 * sizeof (char); out.open(mapped_file_sink(p)); } catch (const std::exception &e) { std::cout << e.what() << std::endl; return 2; } return 0; } // Code snippet When compiled, the execution goes like: c:\>test_shmem somefile c:\>test_shmem somefile failed setting file size: The handle is invalid. I tried without the new_file_size, I tried with a mapped_file... Is there something I don't get? Why are we not able to open a file that already exist? Thanks for your help. JD

4 9

[smart_ptr] shared_ptr clean-up failure
by Robbie Morrison 04 Oct '07

04 Oct '07

Hi all -- hope someone can help, many TIA -- Robbie Intro This relates to the Boost.Smart_ptr library. The example code (see below) fails when a boost::shared_ptr is used, but not when a raw pointer is substituted. This posting probably highlights some key misunderstanding on my part. Perhaps someone can explain where I went wrong. As a long shot, it could be that the Boost.Ref library can offer something useful. Problem I want to pass in an existing UDT (user-defined type) by reference to a second UDT during construction. I figured it would be better to hold this reference in a smart pointer rather than a raw pointer. The following stripped-down code mimics this process, but passes in an int (a fundamental type) instead for reasons of simplicity. The example works fine with a raw pointer, but not a boost::shared_ptr (or std::auto_ptr or boost::scoped_ptr or std::tr1::shared_ptr). I checked in Becker (2007) ("C++ standard library extensions") and Karlsson (2006) ("Beyond the C++ standard library") regarding Boost.Smart_ptr's, but could not see anything useful. 'frag-pass-by-ref_03.cc' was the name of my program. Test environment - Boost release 1.34.1 dated 24-Jul-2007 (source build) - GNU GCC 4.1.2 compiler (using -Wall -Weffc++ -pedantic) - Linux Ubuntu 6.10 operating system (now superseded by 7.04) - run-time memory checking with valgrind version "valgrind-3.2.0-Debian" - laptop is Toshiba Tecra A2 330, new 2004, 1.4GHz Intel Celeron M Error messages (normal run-time) destroying a MyClass *** glibc detected *** ./frag-pass-by-ref_03: free(): invalid pointer: 0xbfcd12dc *** ======= Backtrace: ========= /lib/tls/i686/cmov/libc.so.6[0xb7d8a8bd] /lib/tls/i686/cmov/libc.so.6(__libc_free+0x84)[0xb7d8aa44] /usr/lib/libstdc++.so.6(_ZdlPv+0x21)[0xb7f3afc1] ./frag-pass-by-ref_03(__gxx_personality_v0+0x3d3)[0x8048baf] ./frag-pass-by-ref_03[0x8048c96] ./frag-pass-by-ref_03(__gxx_personality_v0+0x274)[0x8048a50] ./frag-pass-by-ref_03(__gxx_personality_v0+0x29e)[0x8048a7a] ./frag-pass-by-ref_03(__gxx_personality_v0+0x2ba)[0x8048a96] ./frag-pass-by-ref_03[0x8048cd4] ./frag-pass-by-ref_03(__gxx_personality_v0+0x195)[0x8048971] /lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xdc)[0xb7d398cc] ./frag-pass-by-ref_03(__gxx_personality_v0+0x65)[0x8048841] ======= Memory map: ======== (remainder omitted) Error messages (under valgrind) destroying a MyClass ==23254== Invalid free() / delete / delete[] ==23254== at 0x4020CC7: operator delete(void*) (vg_replace_malloc.c:244) ==23254== by 0x8048BAE: void boost::checked_delete<int>(int*) (checked_delete.hpp:34) ==23254== by 0x8048C95: boost::detail::sp_counted_impl_p<int>::dispose() (sp_counted_impl.hpp:79) ==23254== by 0x8048A4F: boost::detail::sp_counted_base::release() (sp_counted_base_gcc_x86.hpp:145) ==23254== by 0x8048A79: boost::detail::shared_count::~shared_count() (shared_count.hpp:205) ==23254== by 0x8048A95: boost::shared_ptr<int>::~shared_ptr() (shared_ptr.hpp:131) ==23254== by 0x8048CD3: MyClass::~MyClass() (frag-pass-by-ref_03.cc:21) ==23254== by 0x8048970: main (frag-pass-by-ref_03.cc:31) ==23254== Address 0xBE8944FC is on thread 1's stack (error summary omitted) 8< ------------------------------------------- #include <iostream> // standard io #include <boost/shared_ptr.hpp> // Boost shared pointer class MyClass { public: MyClass (int& i) // & indicates pass-by-reference : d_int(&i) { } // & is address-of operator ~MyClass() { std::cout << "destroying a MyClass" << std::endl; } private: boost::shared_ptr<int> d_int; // shared pointer FAILS // int* d_int; // raw pointer works }; int main() { int myint(2); // simple integer MyClass myclass(myint); // constructor call return 0; } ------------------------------------------- >8 --- Robbie Morrison PhD student -- policy-oriented energy system simulation Institute for Energy Engineering (IET) Technical University of Berlin (TU-Berlin), Germany [from IMAP client]

2 1

boost-users: boost enable_if
by chun ping wang 04 Oct '07

04 Oct '07

template <typename T> bool boost::pseudoprime(const T& n, const T& k) { typedef boost::operators<T> operatorT; BOOST_STATIC_ASSERT(is_integral<T>::value); // static assert 1. BOOST_STATIC_ASSERT((is_base_of<operatorT, T>::value)); // static assert 2. BOOST_ASSERT (n > T(2) && n % T(2) != 0); return modular_expo(k, n-1, n) != T(1) % n ? true : false; } now in vistual studio 2005 sp1 and visual studio 2008 beta the part "is_base_of<operatorT, T>::value" does not work if T happens to be an int or long due to "error C2803: 'operator --' must have at least one formal parameter of class type". I want to use enable_if to enable the STATIC_ASSERT only if T is NOT an arithmetic type for static assert 2. How would i go about doing that?

2 9

(no subject)
by Mark Beinker 04 Oct '07

04 Oct '07

Hi, I was trying to use the boost interval class using g++ under cygwin, but unfortunately, I have trouble to use the exp function. The following code: #include <iostream> #include <cmath> #include <boost/numeric/interval.hpp> #define DOUBLE boost::numeric::interval<double> int main(int argc, char** argv) { DOUBLE x(4,5); std::cout.precision(19); DOUBLE res = exp(x); std::cout<<'['<<res.lower()<<", "<<res.upper()<<']'<<std::endl; return 0; } generates the following compile error: /usr/include/boost/numeric/interval/transc.hpp: In function `boost::numeric::interval<T, Policies> boost::numeric::exp(const boost::numeric::interval<T, Policies>&) [with T = double, Policies = boost::numeric::interval_lib::policies<boost::numeric::interval_lib::rounded_math<double>, boost::numeric::interval_lib::checking_strict<double> >]': itest.cpp:14: instantiated from here /usr/include/boost/numeric/interval/transc.hpp:34: error: 'struct boost::numeric::interval_lib::rounded_math<double>' has no member named 'exp_down' itest.cpp:14: instantiated from here /usr/include/boost/numeric/interval/transc.hpp:34: error: 'struct boost::numeric::interval_lib::rounded_math<double>' has no member named 'exp_up' I use boost version 1.34.1. Any idea why this doesn't work? Regards, Mark

1 0

[Boost.TypeTraits] Adding specialisations
by Kirit Sælensminde 04 Oct '07

04 Oct '07

I'm wondering if finding the need to add specialisations of boost::detail::function_traits_helper is a result of missing headers, incorrect usage or just things that have not been added to Boost.TypeTraits on purpose? I'm using Boost 1.34.0 RC and MSVC 8.1 SP1. The first set can be seen on http://www.boostcookbook.com/Recipe:/1234841 and the second set on http://www.boostcookbook.com/Recipe:/1234968 namespace boost { namespace detail { template<typename R> struct function_traits_helper<R (**)(void) > { BOOST_STATIC_CONSTANT(int, arity = 0); typedef R result_type; }; template<typename R, typename F, typename L> struct function_traits_helper< boost::_bi::bind_t<R, F, L > * > { BOOST_STATIC_CONSTANT(int, arity = 0); typedef R result_type; }; } } namespace boost { namespace detail { template<typename R, typename C> struct function_traits_helper< R (C::**)(void) const > { BOOST_STATIC_CONSTANT(int, arity = 0); typedef R result_type; typedef C class_type; }; template<typename R, typename C, typename A1> struct function_traits_helper< R (C::**)( A1 ) const > { BOOST_STATIC_CONSTANT(int, arity = 1); typedef R result_type; typedef C class_type; typedef A1 arg1_type; }; template<typename R, typename C, typename A1, typename A2 > struct function_traits_helper< R (C::**)( A1, A2 ) const > { BOOST_STATIC_CONSTANT(int, arity = 2); typedef R result_type; typedef C class_type; typedef A1 arg1_type; typedef A2 arg2_type; }; } } K

3 11

Building Boost 1.34.1 on Solaris 10/SPARC
by Boris 04 Oct '07

04 Oct '07

According to http://blogs.sun.com/sga/entry/boost_mini_howto "upcoming Boost 1.34 works with Sun C++ well out of the box" - can anyone confirm this? I'm trying to upgrade from Boost 1.33.1 to Boost 1.34.1 on Solaris 10/SPARC but ran into problems with both CC (Sun C++ 5.9 SunOS_sparc Patch 124863-01 2007/07/25) and g++ 3.4.6. With "./bjam --toolset=sun stage" I see this error (among others): sun.compile.c++ bin.v2/libs/wave/build/sun/debug/threading-multi/instantiate_cpp_exprgrammar.o "./boost/wave/util/flex_string.hpp", line 529: Error: Formal argument 2 of type void* in call to std::allocator<char>::allocate(unsigned, void*) is being passed const char*. "./boost/wave/util/flex_string.hpp", line 558: Where: While instantiating "boost::wave::util::AllocatorStringStorage<char, std::allocator<char>>::Alloc(unsigned, const void*)". "./boost/wave/util/flex_string.hpp", line 558: Where: Instantiated from static boost::wave::grammars::expression_grammar_gen<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char>>, char*>>>>>::evaluate(const std::list<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char>>, char*>>>>, boost::fast_pool_allocator<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char>>, char*>>>>, boost::default_user_allocator_new_delete, boost::details::pool::null_mutex, 32>>::const_iterator&, const std::list<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char>>, char*>>>>, boost::fast_pool_allocator<boost::wave::cpplexer::lex_token<boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char>>, char*>>>>, boost::default_user_allocator_new_delete, boost::details::pool::null_mutex, 32>>::const_iterator&, const boost::wave::util::file_position<boost::wave::util::flex_string<char, std::char_traits<char>, std::allocator<char>, boost::wave::util::CowString<boost::wave::util::AllocatorStringStorage<char, std::allocator<char>>, char*>>>&, bool, boost::wave::grammars::value_error&). "libs/wave/src/instantiate_cpp_exprgrammar.cpp", line 39: Where: Instantiated from non-template code. 1 Error(s) detected. With "./bjam --toolset=gcc stage" I see that error (again among others): gcc.link.dll bin.v2/libs/thread/build/gcc-3.4.6/debug/threading-multi/libboost_thread-gcc34-mt-d-1_34_1.so.1.34.1 /usr/ccs/bin/ld: illegal option -- start-group /usr/ccs/bin/ld: illegal option -- end-group ... collect2: ld returned 1 exit status As the Boost Mini HOWTO mentions that Boost 1.34 should work out of the box I wonder if I'm the only one having a problem on Solaris? As the Getting Started document mentions that "only very recent versions are known to work well with Boost" - is Sun C++ 5.9 SunOS_sparc Patch 124863-01 2007/07/25 maybe not recent enough? :) Boris

3 4

ublas/ vector proxy/ merging slices
by e r 04 Oct '07

04 Oct '07

hi, i have a vector of the form {x[1],...,x[i-1],x[i],x[i+1],...,x[n]} i'm wondering how to create a slice -if it's at all possible- for {x[1],...,x[i-1],x[i+1],...,x[n]}

1 0

[preprocessor]
by Josh Brown 03 Oct '07

03 Oct '07

Hello, First off, I apologize if this is a redundant post, I'm relatively new to Boost and I couldn't find a link to a list archive and a google search didn't merit anything either. I'm using the preprocessor lib to generate a class definition from a sequence of sequences. I want to be able to make the last element of each sequence optional and generate additional code based on if the last parameter exists. I'm currently testing for the length of the sequence in a BOOST_PP_IF statement to see if it has the optional last parameter. The problem is that both the true and false result expressions are being expanded and then the correct one is selected based on the evaluation; which in my case causes an error. I boiled down my problem to a fairly simple example: //= test.cpp ================================================= #include <boost/preprocessor/seq/for_each.hpp> #include <boost/preprocessor/control/if.hpp> #include <boost/preprocessor/comparison/equal.hpp> #include <boost/preprocessor/seq/size.hpp> #include <boost/preprocessor/seq/elem.hpp> #include <boost/preprocessor/facilities/empty.hpp> #define MY_SEQ ((var1) (VAR1) (option1)) ((var2) (VAR2)) #define GET_OPTIONAL_ELEMENT(r, data, elem) \ BOOST_PP_IF( \ BOOST_PP_EQUAL(BOOST_PP_SEQ_SIZE(elem), 3), \ BOOST_PP_SEQ_ELEM(2, elem), \ BOOST_PP_EMPTY() \ ) #define DEMO_PROBLEM(seq) \ BOOST_PP_SEQ_FOR_EACH(GET_OPTIONAL_ELEMENT, _, seq) DEMO_PROBLEM(MY_SEQ) //= test.cpp ================================================= running the above code through gcc -E generates this error: test.cpp:20:1: error: macro "BOOST_PP_SEQ_ELEM_III" requires 2 arguments, but only 1 given The root of my problem seems to stem from the fact that BOOST_PP_IF expands both the true and false expressions before it does the if test and just outputs the already expanded expression. Is this correct; and if so, is there a way around it? Or are there any obvious other solutions to my problem that the boost experts can suggest :) Thanks Josh Brown

4 4

[multi_key] problems using modify_key with a composite_key index
by Jeff Holle 03 Oct '07

03 Oct '07

Once again, I've run into a compilation problem that I can't seem to fix and I wish some help. My multi_index container looks like: typedef multi_index_container< entry, indexed_by< ordered_unique<member<entry,DataVertex,&entry::m_vertex> >, ordered_non_unique< composite_key< entry, member<entry,size_t,&entry::m_y>, member<entry,size_t,&entry::m_x> > > > > C; I now have to swap values via the composite_key. To simplify things, I'll just express the last of three lines that would do this job if it compiles (and the lines needed to understand it). c.get<1>().modify_key(c.get<1>().find(make_tuple(y,UINT_MAX)),ll::_1=make_tuple(y,startIter2->m_x)); where startIter2 type is: nth_index<C,1>::type::iterator and y is just an int. The compiler error that I get is: $BOOST_ROOT/boost/multi_index/detail/modify_key_adaptor.hpp: In member function 'void boost::multi_index::detail::modify_key_adaptor<Modifier, Value, KeyFromValue>::operator()(Value&) [with Modifier = boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::assignment_action>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, const boost::tuples::tuple<int, unsigned int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, Value = Positioner::entry, KeyFromValue = boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>]': $BOOST_ROOT/boost/multi_index_container.hpp:543: instantiated from 'bool boost::multi_index::multi_index_container<Value, IndexSpecifierList, Allocator>::modify_(Modifier, typename boost::multi_index::detail::multi_index_base_type<Value, IndexSpecifierList, Allocator>::type::node_type*) [with Modifier = boost::multi_index::detail::modify_key_adaptor<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::assignment_action>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, const boost::tuples::tuple<int, unsigned int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, Positioner::entry, boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >, Value = Positioner::entry, IndexSpecifierList = boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_vertex>, mpl_::na, mpl_::na>, boost::multi_index::ordered_non_unique<boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, Allocator = std::allocator<Positioner::entry>]' $BOOST_ROOT/boost/multi_index/detail/index_base.hpp:166: instantiated from 'bool boost::multi_index::detail::index_base<Value, IndexSpecifierList, Allocator>::final_modify_(Modifier, typename boost::multi_index::detail::multi_index_node_type<Value, IndexSpecifierList, Allocator>::type*) [with Modifier = boost::multi_index::detail::modify_key_adaptor<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::assignment_action>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, const boost::tuples::tuple<int, unsigned int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, Positioner::entry, boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >, Value = Positioner::entry, IndexSpecifierList = boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_vertex>, mpl_::na, mpl_::na>, boost::multi_index::ordered_non_unique<boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, Allocator = std::allocator<Positioner::entry>]' $BOOST_ROOT/boost/multi_index/ordered_index.hpp:338: instantiated from 'bool boost::multi_index::detail::ordered_index<KeyFromValue, Compare, SuperMeta, TagList, Category>::modify(boost::multi_index::detail::bidir_node_iterator<boost::multi_index::detail::ordered_index_node<typename SuperMeta::type::node_type>, mpl_::na>, Modifier) [with Modifier = boost::multi_index::detail::modify_key_adaptor<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::assignment_action>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, const boost::tuples::tuple<int, unsigned int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, Positioner::entry, boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >, KeyFromValue = boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, Compare = std::less<boost::multi_index::composite_key_result<boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, SuperMeta = boost::multi_index::detail::nth_layer<2, Positioner::entry, boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_vertex>, mpl_::na, mpl_::na>, boost::multi_index::ordered_non_unique<boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, std::allocator<Positioner::entry> >, TagList = boost::mpl::vector0<mpl_::na>, Category = boost::multi_index::detail::ordered_non_unique_tag]' $BOOST_ROOT/boost/multi_index/ordered_index.hpp:349: instantiated from 'bool boost::multi_index::detail::ordered_index<KeyFromValue, Compare, SuperMeta, TagList, Category>::modify_key(boost::multi_index::detail::bidir_node_iterator<boost::multi_index::detail::ordered_index_node<typename SuperMeta::type::node_type>, mpl_::na>, Modifier) [with Modifier = boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::assignment_action>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, const boost::tuples::tuple<int, unsigned int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, KeyFromValue = boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, Compare = std::less<boost::multi_index::composite_key_result<boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, SuperMeta = boost::multi_index::detail::nth_layer<2, Positioner::entry, boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_vertex>, mpl_::na, mpl_::na>, boost::multi_index::ordered_non_unique<boost::multi_index::composite_key<Positioner::entry, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_y>, boost::multi_index::member<Positioner::entry, unsigned int, &Positioner::entry::m_x>, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, std::allocator<Positioner::entry> >, TagList = boost::mpl::vector0<mpl_::na>, Category = boost::multi_index::detail::ordered_non_unique_tag]' Can somebody point out whats wrong?

7 13

Building static version of boost with bjam
by Michael Bradley Jr 03 Oct '07

03 Oct '07

Hi, how can i build boost as a static + mt library using bjam? I've tried the following command *bjam --toolset=msvc stage* without greater success. Getting a lot of warning and even single-threaded version are built ;( Is there a way to specify what is to be built? If yes how? Thanks in advance for any reply - Michael My System: WindowsXP SP2 (32bit) Visual Studio 2005

2 1

question on boost::regex expression(query);
by Mike Marchywka 03 Oct '07

03 Oct '07

Hi, I'm new to boost and not all that familiar with Perl regex. However, I have my own code for using Perl regex libraries for finding interesting features in DNA ( http://www.mail-archive.com/bio_bulletin_board@bioinformatics.org/msg01382.… ) I recently added boost to work along with Microsoft's greta code. However, I now have a problem with regex exploding. The questionable regex is presumably, (?<=GU.*?TACTAAC.{20,40}AG|^).*?(?=GU.*?TACTAAC.{20,40}AG|$) ( which doesn't explode with greta AFAIK) and the code in question is ( MM_MARK is debug macro, es is error stream other stuff omitted). try { es<<MM_MARK<<" "<<" "<<'\n'; boost::regex expression(query); [...] es<<MM_MARK<<" "<<" "<<'\n'; [ ...] } catch ( boost::regex_error e) { es<<MM_MARK<<" Error code "<<e.code()<<" at "<<e.position()<<'\n'; es<<MM_MARK<<query<<'\n'; return -1; } catch (exception e) { es<<MM_MARK<<" "<<e.what()<<'\n'; es<<MM_MARK<<" at "<<(start-sample)<<" for regex "<<query <<".\n"; } catch (...) { es<<MM_MARK<<" "<<"Unknown exception \n";} return -1; } I have two questions, what is wrong with the regex and how do I trap the error? The program just dies with "Aborted( core dump)." I guess there could be a build problem but I thought it may be something obvious that I am doing wrong in the regex or calling the library. Thanks. Mike Marchywka 586 Saint James Walk Marietta GA 30067-7165 404-788-1216 (C)<- leave message 989-348-4796 (P)<- emergency only marchywka(a)hotmail.com Note: Hotmail is blocking my mom's entire ISP claiming it is to reduce spam but probably to force users to use hotmail. Please DON'T assume I am ignoring you and try me on marchywka(a)yahoo.com if no reply here. Thanks. _________________________________________________________________ Test your celebrity IQ. Play Red Carpet Reveal and earn great prizes! http://club.live.com/red_carpet_reveal.aspx?icid=redcarpet_hotmailtextlink2

2 12

[multi_index] nested struct question
by boost＠larroy.com 03 Oct '07

03 Oct '07

Hi. I'm trying to create a multi_index and I was wondering if its possible to use a member of a member struct as index. struct nested_element_t { int i; }; struct element_t { nested_element_t ne; }; I'm not sure if there's a way to use member key extractor or should I write my own typedef multi_index_container< element_t, indexed_by< ordered_non_unique<tag<h>, member<nested_element_t ? , int, &nested_element_t> > > > set_t; Regards. -- Pedro Larroy Tovar, pedro at larroy dot com | http://pedro.larroy.com/ * Las patentes de programación son nocivas para la innovación * http://proinnova.hispalinux.es/

2 1

How to build on win64 with intel?
by Nicholas Bastin 03 Oct '07

03 Oct '07

I'm trying to build on WinXP 64 with the following command line: bjam --toolset=intel address-model=64 --with-signals stage However, every compile-c-c++ line gives me a popup window on my machine stating: "Windows cannot open this file: File: trackable.obj.rsp To open this file, Windows needs to know what program created it. Windows can go online....blah blah blah blah" And of course my build fails. Anyone know what to do about this, or what is screwed up in my environment? -- Nick

4 4

Regex and Win CE
by Ken Perry 03 Oct '07

03 Oct '07

Well hopefully this email will not get held by the moderator again. I have been trying to find out how I would go about compiling the Regex library with Visual studio 2005 for Win CE. I have seen some defines for Win CE so it looks like people are working on it. If no one has finished it then I will just grab the library and compile it myself. If however there is some thing I have to do at the command line of Jam I would like to know that before I go and try and fix it myself. Ken

2 2

Boost cookbook site (alpha)
by Kirit Sælensminde 03 Oct '07

03 Oct '07

I've spent the weekend putting together a cookbook site. I hope nobody minds. People can explore and play with it at http://www.boostcookbook.com/ Any problems, issues or suggestions can be reported at http://www.boostcookbook.com/Site:/Issues Apart from a couple of ASP pages using JavaScript the site is in C++ and makes heavy use of Boost :) Kirit

10 19

Reproducible access violation on win64 with signals (example code)
by Nicholas Bastin 02 Oct '07

02 Oct '07

I've managed to get my signals access violation to happen in a relatively simple test program on win64. I'm attaching my example source code to this email. If anyone needs anything else to reproduce the problem, please let me know. This program works when statically linked, but not when dynamically linked, so if someone can spot a bad compiler/linker flag, that would help too. I built boost with: bjam --toolset=intel address-model=64 link=shared runtime-link=shared --with-signals stage Also, I had to edit intel-win.jam to change icc.exe to icl.exe so that the compiler would run properly. I built my test application with: icl /EHsc /MD /I. test.cpp /link /subsystem:console /LIBPATH:stage\lib /NODEFAULTLIB /ENTRY:mainCRTStartup /FORCE:multiple boost_signals-iw-mt-1_34.lib msvcprt.lib msvcrt.lib libirc.lib libmmd.lib If you build with static linkage (obviously, rebuild boost without the shared link settings), the executable works fine (with libboost_signals-iw-mt-1_34.lib). -- Nick

1 0

statechart - time event...implementation ?
by Raja Cherukuri 02 Oct '07

02 Oct '07

It seems the current implementation of statechart library does not have timed event. It is possible to extend or specialize the current event<> class to achieve this ? Has anyone done this yet ? Looks like a common requirement for this type of event. Any reason why it is not part of this library offering ? Is it expected that users of this library do it themselves ? Thanks in advance. - Raja

2 3

Using boost (maybe mpl?) to generalize a switch statement to call different template functions
by Peng Yu 02 Oct '07

02 Oct '07

Hi, I have the following program, which uses a switch statement to call different template functions. The example is simple, but as the number of shapes increase, the switch statement might be very hard to maintain. I'm looking for a more general solution (maybe using mpl, not sure), such that the switch statement can be automatically generated, therefore, more maintainable. Thanks, Peng #include <iostream> enum shape { circle, square // there might be many cases }; template <shape, shape> struct A { void doit() const; }; //doit functions are defined for a majority number of shape combinations (maybe not all, but could be defined for all---the bodies of the functions not need can be empty). // 3 case. There should be 4 doit's if we consider all combinations. template <> void A<circle, circle>::doit() const { std::cout << "circle circle" << std::endl; } template <> void A<circle, square>::doit() const { std::cout << "circle square" << std::endl; } template <> void A<square, circle>::doit() const { std::cout << "square circle" << std::endl; } void f(shape s1, shape s2) { // each defined shape-combination corresponds to one case // I want to generalize the code by using boost::mpl // (or some other packages if applicable) switch(s1 << 8 | s2) { case circle << 8 | circle: A<circle, circle>().doit(); break; case circle << 8 | square: A<circle, square>().doit(); break; case square << 8 | circle: A<square, circle>().doit(); break; default: std::cout << "not defined" << std::endl; } } int main() { f(circle, circle); f(circle, square); f(square, circle); f(square, square); }

3 3

[signals] call a slot only once
by Christian Holmquist 02 Oct '07

02 Oct '07

Hello, Is there a way to automatically have a slot disconnected after it has been called once, without managing the connection manually? void f() { } signal<void()> sig; sig.connect(&f); sig(); // f gets called sig(); // f shouldn't get called

2 4

Usage of iterator_facade and iterator_adaptor
by Peng Yu 02 Oct '07

02 Oct '07

Hi, I'm trying to use Boost.Iterator library. I understand that iterator_adaptor specialize some part of iterator_facade. However, I can not tell for what application I should use iterator_facade or iterator_adaptor. I think the manual should summarize this for the user. Can somebody give me some hint on which to use them and under what condition, if you have the experience? Thanks, Peng

2 1

[boost::enable_shared_from_this] in inheritance tree throws bad_weak_ptr exception
by dariomt＠gmail.com 02 Oct '07

02 Oct '07

I need to create a class hierarchy where every level inherits from boost::enable_shared_from_this. I am having problems caused, I believe, by having more than one copy of enable_shared_from_this. I am using boost 1.34.1 with VS2003 and VS2005, with and without ICL9.1, always getting the same result: a boost::bad_weak_ptr exception. #include <boost/shared_ptr.hpp> #include <boost/enable_shared_from_this.hpp> using namespace boost; struct A : enable_shared_from_this<A> { shared_ptr<A> getA() {return enable_shared_from_this<A>::shared_from_this();} }; struct B : A, enable_shared_from_this { shared_ptr getB() {return enable_shared_from_this::shared_from_this();} }; int main() { shared_ptr<A> pA (new A); pA->getA(); // this works OK shared_ptr pB (new B); pB->getB(); // throws boost::bad_weak_ptr() !? return 0; } question 1: Is this expected or am I doing something wrong? question 2: If it is expected: is it possible to have it explained in the documentation? question 3: Is there a way to accomplish this (inheritance with shared_from_this in all levels) using enable_shared_from_this? Thanks in advance

3 3

[Process] getcwd memory leak in context.hpp
by Chris Fairles 02 Oct '07

02 Oct '07

Valgrinding the single_process_tutorial example, it seems getcwd in context.hpp is called with a NULL buffer and 0 size meaning that space is automagically malloc'd (according to POSIX.1-2001). ==10383== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 5 from 1) ==10383== malloc/free: in use at exit: 64 bytes in 1 blocks. ==10383== malloc/free: 32 allocs, 31 frees, 22,225 bytes allocated. ==10383== For counts of detected errors, rerun with: -v ==10383== searching for pointers to 1 not-freed blocks. ==10383== checked 162,760 bytes. ==10383== ==10383== 64 bytes in 1 blocks are definitely lost in loss record 1 of 1 ==10383== at 0x4A0590B: realloc (vg_replace_malloc.c:306) ==10383== by 0x39848C03FC: getcwd (in /lib64/libc-2.5.so) ==10383== by 0x407894: boost::process::basic_work_directory_context<std::string>::basic_work_directory_context() (context.hpp:85) ==10383== by 0x407A19: boost::process::basic_context<std::string>::basic_context() (context.hpp:142) ==10383== by 0x403730: main (single_process_tutorial.cpp:44) ==10383== ==10383== LEAK SUMMARY: ==10383== definitely lost: 64 bytes in 1 blocks. I think the memory should be free()'d if the returned buf isnt NULL (or create a buffer isntead of passing NULL,0). Chris

1 0

identical boost expression used in different parts of the code - looking for an alias
by e r 02 Oct '07

02 Oct '07

hi for example, i use boost::bind( &A::f, _1 ) in different parts of my code. how can i define an alias for this expression? i'm thinking of using something like some_type* fo = new boost::bind(&A::f,_1); and use *fo in place of boost::bind(...). is this crazy? what should some_type be?

3 3

boost::shared_ptr and "this"-pointer: how to use shared_from_this?
by Taneli R. 02 Oct '07

02 Oct '07

I'm converting pipes and filters architecture made with raw pointers to use shared_ptrs. My Pipe class has a static counter, which gives unique pipeID to every pipe. Since Pipe class has pure virtual functions, the pipes in my architecture are instances of derived classes. Pipe class looks like this: class Pipe { public: Pipe() : pipeID(++pipeCount) {} virtual bool lay(boost::shared_ptr<Pipeable>& source, string& sourceTag, boost::shared_ptr<Pipeable>& destination, string& destTag) = 0; /*...other pure virtual functions here...*/ protected: int pipeID; static int pipeCount; } My problem is that when I try to make a new pipe between source and destination, the pipe is made twice (with different pipeID-numbers), which is a problem because there should be only one pipe connecting my components. I believe it is a result from using "this"-pointer directly without enabling "shared_from_this". I know that I should use it somehow but the same time I should maintain the unique pipeID. If I create a new shared_ptr with "shared_from_this" enabled inside SimplePipe, it has a different pipeID than the one I should be using. I have to use shared_ptr because I'm storing pointers into containers. And finally I cannot instantiate Pipe directly from its base class with using "shared_from_this" because it has pure virtual functions. Any help for solving this problem or a decent tutorial on using shared_ptrs and enable_shared_from_this would be appreciated. The following code snippets illustrate the problem: // //Main // boost::shared_ptr<Pipe> pipe; pipe = inputPipes[tag]; //find a matching pipe from the map if (pipe.get() == 0) //if not found, create a new pipe { boost::shared_ptr<Pipeable> source; // no source boost::shared_ptr<Pipeable> destination (boost::dynamic_pointer_cast<Pipeable>(comp)); pipe = boost::shared_ptr<Pipe>(new SimplePipe(source, srcTag, destination, destTag)); //creating new pipe inputPipes[tag] = pipe; //put the pipe into a map } // //SimplePipe, derived from Pipe // SimplePipe::SimplePipe(boost::shared_ptr<Pipeable>& source, string& sourceTag, boost::shared_ptr<Pipeable>& destination, string& destTag) { lay(source, sourceTag, destination, destTag); } bool SimplePipe::lay(boost::shared_ptr<Pipeable>& source, string& sourceTag, boost::shared_ptr<Pipeable>& destination, string& destTag) { if (source.get() != 0 && destination.get() != 0 && !sourceTag.empty() && !destTag.empty()) //Both ends attached { if (source->makeSource(pipeID, sourceTag)) { this->source = source; //problem? if (destination->makeDestination(pipeID, destTag)) { this->destination = destination; //problem? return true; } else { source->detachPipe(pipeID); } } } else if (source.get() == 0 && destination.get() != 0 && !destTag.empty()) //only destination attached { if (destination->makeDestination(pipeID, destTag)) { this->destination = destination; //problem? return true; } } else if (source.get() != 0 && destination.get() == 0 && !sourceTag.empty()) { /*etc etc...*/ } return false; } -- View this message in context: http://www.nabble.com/boost%3A%3Ashared_ptr-and-%22this%22-pointer%3A-how-t… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

[boost::graph] creating an external map for depth_first_search
by v r 02 Oct '07

02 Oct '07

I cannot figure out how to create a color map for depth first search, i`m using bundled properties and the following type as graph. adjacency_list<listS,setS,bidirectionalS,WorldNode> world_graph_t; right now i`m trying to make it like this, but i get 50 errors and cannot deduce what my error is. template<class VisitorT> THOR_INLINE void DepthFirstSearch(const VisitorT& vis, const vertex_descriptor& start) { using namespace boost; std::vector<default_color_type> color_vec( num_vertices(graph) ); depth_first_search(graph, visitor(vis), color_map(make_iterator_property_map(color_vec.begin(),get(vertex_color,graph))), start); } --------------------------------- Вы уже с Yahoo!? Испытайте обновленную и улучшенную. Yahoo! Почту!

3 2

Bjam linking problem
by desai3＠cooper.edu 02 Oct '07

02 Oct '07

Hi folks: I have successfully wrapped up a C++ program in Python. Now I want to give my libboost_python.so and server.so files to my friend, so that he can use it too. However server.so makes use of libstdc++ and ssl library files, which I have to link statically to the server.so in order to be able to give server.so to someone. However Bjam is not linking libstdc++.a or libssl.a to server.so statically. I will really appreciate if someone could give me any direction about how to link these libraries statically to server.so . Thank you very much. Maulik P.S. My Jamfile looks like this ----------------------------------------------------------------------- project-root ; import python ; extension server : server.cpp <template>@boost/libs/python/build/extension : <include>. <include>../dqp <include>/export/apps/dq/dqweb/include <library-path>/home/o066144/work_in_progress/api/SunOS-5.8-g++ <library-path>/export/apps/dq/dqweb/lib <library-path>/usr/local/lib <find-library>ssl <find-library>crypto <find-library>dl <find-library>socket <find-library>nsl <find-library>gcc <find-library>stdc++ ; ---------------------------------------------------------------------------

2 2

BGL: traveling salesman problem
by Michael Held 02 Oct '07

02 Oct '07

hi bgl-guys, is there a 'traveling salesman' implementation for bgl or is anything in this direction planned? there are several algorithms available, e.g. http://www.tsp.gatech.edu/concorde.html which could be ported to bgl?! best regards, michael

1 0

dumb question about boost::any.
by chun ping wang 02 Oct '07

02 Oct '07

How would i go about implementing operator< for boost::any....

1 0

[program_options] Why is allow_unregistered not implemented for config file?
by Marty Fried 01 Oct '07

01 Oct '07

I want to use the program_options library for my app's, well, program options. There is one set of options, which will usually only be one or two lines, that will have an unknown name; this is only handled by the (boost::program_options::) basic_command_line_parser template, with, apparently, no equivalent functionality for config files. This seems to me to be an oversight. I would have thought there would at least be an option to ignore unknown parameters if they aren't supported like for the command line. For my needs, it looks like I might need to modify the Boost sources to disable the exception on unknown parameters, or force the user to create a special config file for, most likely, a single parameter. Or I can change the syntax to something much less natural. What I'm hoping for is either someone to inform me that I'm wrong, and there is a way to handle config files more elegantly than what I'm seeing, or a suggestion as to how best to implement what I need. Thanks for any help you can offer. -- Marty Fried - email: public.forums (at) gmail.com Left coast, USA

2 2

Boost license / OSI approved
by Ruediger Berlich 01 Oct '07

01 Oct '07

Hi there, I noticed that the Boost license is not listed as an OSI approved license (see here: http://www.opensource.org/licenses/alphabetical ). Why is this ? The license seems to nicely comply with the Open Source definition, from what I can see (see http://www.opensource.org/docs/osd) http://www.fsf.org/licensing/licenses/ lists it as GPL-compatible. Best Regards, Ruediger

4 3

thread, use case: one manager and several worker threads
by Torsten Mohr 01 Oct '07

01 Oct '07

Hi, i have a question regarding boost::thread on general usage. I have a calculation intense problem that can be parallelised quite well. But i'd like the whole thing to be interruptible, so when the user commands to stop calculationg then the threads should stop working on the problem. I don't know how to set this up in principle, some thoughts: I want to create one manager thread and several worker threads. The manager thread commands the worker threads on what job to work. When a worker thread has finished, it tells the manager thread so and can get another job to work on. If a user commands the manager thread to stop working, the manager thread commands the worker threads to stop as soon as possible. I think these are quite some normal requirements, but i don't know how to implement this using boost::thread. What is the preferred way to send commands to threads? Just lock a mutex that is shared with the thread and then write a shared variable? How can a manager thread wait on several worker threads at once without wasting CPU time? How does a worker thread notify the manager thread? I can't see how this can be done with boost::condition, do i miss something? Or is it possible for the worker thread to share a boost::mutex with every worker thread, let the manager thread lock those mutexes? It then can only do "condition->wait" on _one_ of the conditions. Best regards, Torsten.

1 0

one reason I suspect a build problem in prior post,
by Mike Marchywka 01 Oct '07

01 Oct '07

when I added the code to trap the regex_error, the previously clean build returned the following during linking but I didn't think it would be a problem: Info: resolving vtable for boost::regex_errorby linking to __imp___ZTVN5boost11r egex_errorE (auto-import) I'm linking to /libboost_regex-gcc-mt-1_33_1.a and cygboost_regex-gcc-mt-1_33_1.dll Thanks again. [ I decided to add boost while using my mom's machine and I found out I had accidentally included boost in "her" cygwin install so it is quite likely I botched something ] Mike Marchywka 586 Saint James Walk Marietta GA 30067-7165 404-788-1216 (C)<- leave message 989-348-4796 (P)<- emergency only marchywka(a)hotmail.com Note: Hotmail is blocking my mom's entire ISP claiming it is to reduce spam but probably to force users to use hotmail. Please DON'T assume I am ignoring you and try me on marchywka(a)yahoo.com if no reply here. Thanks. _________________________________________________________________ Test your celebrity IQ. Play Red Carpet Reveal and earn great prizes! http://club.live.com/red_carpet_reveal.aspx?icid=redcarpet_hotmailtextlink2

1 0

date_time time_duration getting milliseconds
by Sebastian Hauer 01 Oct '07

01 Oct '07

Hi Boost Users, I've started using boost's date_time library recently which I find quite convenient for the most part. I have to handle times with sub second parts frequently and was wondering what the recommended way is to extract the milliseconds part of a time_duration instance? It seems there is no time_duration.milliseconds() method available and fractional_seconds() is platform dependent. BTW: I am currently using boost 1.34.1. Regards, Sebastian

1 0

u32regex_search crashes
by Anjaly 01 Oct '07

01 Oct '07

Hello, I am new to Boost-regex library. The libray is build with icu support.The user interface is created using wxWidgets library. I want to search a file using u32regex_search. But the program crashes and the error it shows is 'Invalid UTF-8 sequence encountered while trying to encode UTF-32 character'.I am reading the contents of the file and it is stored in char array.The program is crashing when it encounters a char with hex value 00. wxString s=SearchTxt->GetValue(); const char *start=(const char*)buffer; const char *end=(const char*)buffer+len; boost::cmatch what; boost::u32regex e1= boost::make_u32regex(s.fn_str(), boost::regex::icase); while(boost::u32regex_search(start,end, what,e, boost::match_default)) { cout << what[0] << "\n"; } ______________________________________ Scanned and protected by Email scanner

3 9

Problem in calculating cycle sequence...
by abhishek.v＠tcs.com 01 Oct '07

01 Oct '07

Hi I m able to calculate whether the cycle exist in the graph or not. With the help of following code.. //Finding out cycles struct cycle_detector : public dfs_visitor<> { cycle_detector( bool& has_cycle, int& num):_has_cycle(has_cycle),cycle(num) { } template <class Edge, class Graph> void back_edge(Edge, Graph&) { cycle++; _has_cycle = true; } protected: bool& _has_cycle; int& cycle; }; int main () { ...... .... .... //Finding out whether the graph has cycles.. bool has_cycle = false; int count_cycle=0; typedef Traits::vertices_size_type size_type; cycle_detector vis(has_cycle,count_cycle); boost::depth_first_search(g, visitor(vis)); if(has_cycle) { file_op << "\nThe graph is cyclic"<< std::endl; file_op<<"\nNumber of cycles in the graph is "<<count_cycle; } else std::cout << "The graph is acyclic"<< std::endl; return 0; } Now what i want is to calculate the vertex between which the cycle exist ... How to calculate that.. Thanks Abhishek Vyas Tata Consultancy Services Mailto: abhishek.v(a)tcs.com Website: http://www.tcs.com ____________________________________________ Experience certainty. IT Services Business Solutions Outsourcing ____________________________________________ =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you

1 0

string_algo no replace_if
by gast128 01 Oct '07

01 Oct '07

Dear all I was requesting an 'erase_if' a while ago, and now I ran into a 'replace_if' problem. So after spendig 2 hours in the documentation, I finally found on www ('[string_algo] replace repeated char with single instance?') that one should use the 'find_format_all': boost::find_format_all(str, boost::token_finder(boost::is_any_of("ab")), boost::const_formatter("c")); But wouldn't it be better to make a 'replace_if' shortcut solely for the purpose of documentation reasons: boost::replace_all_if(str, boost::is_any_of("ab"), "c"); I think that most people find the last line easier to read and comprehend than its (more powerful) 'find_format' cousin. The string_algo library is nice but I get lost more than once. Especially find, replace, erease with predicates are often used by us. However direct use seems not possible. wkr, me

2 2

Passing extra compiler arguments with bjam
by Cory Nelson 01 Oct '07

01 Oct '07

I'm wanting to pass some extra arguments for VC++ whole program optimization (specifically, /GL to the compile, /LTCG to the linker). Does anyone know how? -- Cory Nelson

1 0

Problem in calculating critical path and fundamental ckts
by abhishek.v＠tcs.com 01 Oct '07

01 Oct '07

Hi.. I want to calculate the critical paths of a graph using BGL. So what i did is i calculated the connected components of a graph then remove the edge one by one if the number of connected component increase then the edge is critical edge or a bridge. This works fine in case of undirected graph. But how do i calculate connected component of a directed or Bidirected graph i m able to calculate the strongly connected component but it is not helping me out. Can you suggest me something regarding this. Also i want to calculate the fundamental ckt that exist in a graph now. What i did here is i m calculating K-MST. Now i want to calculate the fundamental ckt how should i do that... Thanks Abhishek Vyas Tata Consultancy Services Mailto: abhishek.v(a)tcs.com Website: http://www.tcs.com ____________________________________________ Experience certainty. IT Services Business Solutions Outsourcing ____________________________________________ =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you

1 0

Inquiring about the feasibility of boost::mpl based statechart DSELs that generate boost::statechart based components
by Tony Turner 01 Oct '07

01 Oct '07

Greetings; I am currently experimenting with the feasibility of writing a boost::mpl based library of metaprograms that process statechart DSEL language phrases ( see ref #1 below), that then specifically generate boost::statechart based components. I would be most grateful to hear from others regarding both difficulties to this approach, as well as success stories. If this approach seems feasible, I would like to contribute the resultant code back to the open source community. Since I'm not sure how the contribution process works, I would appreciate it if someone could point me in the right direction. Reference (#1) ( the statechart developed in chap 11, "A DSEL Design Walkthrough" in Abrahams and Gurtovoy's "C++ Template Metaprogramming book".) Thankyou very much for your time; Tony Turner R&D Software Engineer

2 2

Re: [Boost-users] How does one build the asio system library?
by console shark 30 Sep '07

30 Sep '07

Yeah I mean Boost.System, but that wasn't part of the boost download, it seems to come with Asio, right? So now that I put the /system stuff in there, how does it get built? As far as I know it wasn't there prior to me putting it in the /boost/ directory. ----- Original Message ---- From: Richard Dingwall <rdingwall(a)gmail.com> To: boost-users(a)lists.boost.org Sent: Sunday, September 30, 2007 6:04:13 PM Subject: Re: [Boost-users] How does one build the asio system library? On 10/1/07, console shark <consolejoker(a)yahoo.com> wrote: The docs say to run bjam inside /boost/libs/system/build I did this, and it claims to have built the file but I can't fine it anywhere on my hard drive. Subsequent attempts to run bjam don't seem to do anything. The Asio library is header only. You don't need to build anything. You may however need to link against the Boost.System and Boost.Regex libraries. Richard ____________________________________________________________________________________ Got a little couch potato? Check out fun summer activities for kids. http://search.yahoo.com/search?fr=oni_on_mail&p=summer+activities+for+kids&…

1 0

Serialization recursive include problem
by Fred Lupien 30 Sep '07

30 Sep '07

Hi, I am using the boost serialization library in a personal project and ran into a recursive include problem. Class A serialize an object of class B and class B also serialize an object of class A. So class A must be a complete type in class B and class B must be a complete type in class A, hence the recursive include problem. A easy way to fix this would be to put the serialization code in the source file instead of the header file but I can't get this to work... I always end up with unresolved externals if the body of my serialization functions are not within the header file. Any way around this beside switching to non-intrusive serialization? thanx! -- Frédérick Martel-Lupien Étudiant en Génie Informatique Université de Sherbrooke fred.lupien(a)gmail.com

2 3

How does one build the asio system library?
by console shark 30 Sep '07

30 Sep '07

The docs say to run bjam inside /boost/libs/system/build I did this, and it claims to have built the file but I can't fine it anywhere on my hard drive. Subsequent attempts to run bjam don't seem to do anything. ____________________________________________________________________________________ Looking for a deal? Find great prices on flights and hotels with Yahoo! FareChase. http://farechase.yahoo.com/

2 1

serialization -- thank you!
by Ed Hill 30 Sep '07

30 Sep '07

Hi folks, Many thanks to the Boost developers (esp. Robert Ramey) for the serialization library. I've been tinkering with (de-)serialization of derived classes through base pointers and it works so nicely. thanks again! Ed -- Edward H. Hill III, PhD | ed(a)eh3.com | http://eh3.com/

1 0