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A problem on using boost timer (different time intervals were showed). Can any one with kindness help me?
by fmingu 25 Sep '09

25 Sep '09

I am using boost timer in C++ builder 2009 to test the time used in my program.there are the lines: .................... boost::timer t; double timeresult; ................... t.restart(); ........... //my program main body timeresult=t.elapsed(); ShowMessage( " the time consumed by my program is "+FloatToStr(timeresult)); ......................... the program was compiled and linked and worked well. But I find a problem: every time the message showed is not the same time interval, sometimes it is 0.015 and sometimes it is 0.016 and sometimes it is 0. I do not know how it was happened. Does it happen due to the multi-process and multi-thread mode by windows? I do not know how to solve it. My program is quite strict on the time consumed by the computer. Can any one with kindness help me?

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[lambda] Defining a predicate for std::find_if if the key to a std::map is std::pair
by Ryan McConnehey 25 Sep '09

25 Sep '09

I have the following std::map signature. typedef std::pair<std::string, int> cPair; typedef std::map<cPair, std::vector<classA> > cMap; cMap myMap; When entering values into the map, the std::string is the only part of the key that needs to be unique. Upon retrieving map values both values of the key need to be compared. I've tried to define my insert comparison as follows, but am uncertain how to define the predicate with boost::lambda. std::string givenName = "some_text_value"; int givenInt = 3; cMap::const_iterator itor = std::find_if( myMap.begin(), myMap.end(), boost::lambda::bind( ??? , _1) == givenName ); What goes at the question marks? Ryan

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[spirit] parsing vsv files with embedded quotes/line breaks
by Sean Farrow 25 Sep '09

25 Sep '09

Hi: I know there is a spirit example to parse csv or any list-separated file. What I need to do is to be able to parse files with embedded "," characters, quotes and line breaks in. How would i go about doing this? Regards Sean.

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[MPL] at<> function with too many arguments
by Ryan McConnehey 25 Sep '09

25 Sep '09

I have a mpl::map as follows, with a template parameter of a passed in type and a template parameter of "supported_type" that is a class. using boost::mpl; enum { value = 1 + supported_type::value }; typedef typename insert<typename supported_type::type_map, pair<T, int_<value> > >::type type_map; I'm trying to create a function that searches the map for a given type and returns a numeric value if it's found or -1 if it's not found. template <typename S> int typeValue(void) { return at< type_map, S, int_<-1> >::type::value; } The documentation says I can specify a default value for "at" that is returned if the given key isn't found. The compiler, though, says that I've provided too many arguments. Have I called "at" incorrectly? Is the documentation incorrect? Is the fault with the compiler (VS 2005)? Ryan

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[python] Ownership of python objects.
by Germán Diago 24 Sep '09

24 Sep '09

Hello. I'm trying to do the following thing: 1.- Create an object 2.- Put it in an scene (for a game) 3.- To be able to delete it from the scene (this is done from C++) My problem is that if I do the following: p = Object("blabla") Scene.addToScene("myobject", p) //Here, the object is deleted by C++, which is causing problems p.removeFromScene("myobject") I know a workaround for this. It would be to make a wrapper for objects created from python and not deleting the object if it was created from there. But I would like if there is some other (more general) way to avoid this. Thanks in advance.

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[MultiIndex] documentation for macros
by Igor R 24 Sep '09

24 Sep '09

Hello, Is there any description of the various macros that control MI behavior, like BOOST_MULTI_INDEX_ENABLE_SAFE_MODE etc.? I tried to search through the library reference, but haven't managed to find any. Thanks.

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Re: [Boost-users] [Regex] Group of number at line end
by Roland Bock 24 Sep '09

24 Sep '09

Reiner Hutsch wrote: > -----Ursprüngliche Nachricht----- > Von: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] Im Auftrag von John Maddock > Gesendet: Mittwoch, 23. September 2009 18:45 > An: boost-users(a)lists.boost.org > Betreff: Re: [Boost-users] [Regex] Group of number at line end > >> i am looking for a regular expression which extracts a group of number >> from >> the end of a line like the following: >> >> "This line may contain digits (9) but ends with numbers like 1 2 3 4 5" >> >> When using a regex like "^(.+)(\\s+(\\d+))+$" I receive >> "This line may contain digits (9) but ends with numbers like 1 2 3 4" and >> "5". >> >> Can someone help me? > > What about: "^(.+)[^\\d\\s](\\s+\\d+)+$" > > HTH, John. > > Hi John, > > sorry, but this gives also only the last number. > > Reiner. If you want the group, not the each number separately, this should work: ^.*[^ 0-9] *([ 0-9]+)$ Testing with perl: perl -e '$x = "This line may contain digits (9) but ends with numbers like 1 2 3 4 5"; $x =~ s/^.*[^ 0-9] *([ 0-9]+)$/$1/g; print "$x\n";' Output: 1 2 3 4 5 Regards, Roland

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redirect flow with Breadth-First-Search - problems with the residual capacities
by Benjamin Rupp 24 Sep '09

24 Sep '09

Hi, I want to redirect Flow, which I have earlier calculated with Edmonds-Karp, with Breadth-First-Search (Aim is to determine the maximal free capacity of an edge by redirecting all possible flow to other edges) When I call Edmonds-Karp the Maximal Flow is calculated. If I then print out the values of the residual capacities of the edges, all edges with a capacity of 0 (this are the reverse edges) have a residual capacity of 0 instead of a capacity equal to the flow of the reverse edge. I wrote the following code to correct the values: long speicher[num_edges(g)]; for(tie(e_iter,e_end)=edges(g); e_iter!=e_end; ++e_iter) if(get(e_index,*e_iter) < num_edges(g)/2){ speicher[e_index[*e_iter]] = residual_capacity[*e_iter]; speicher[e_index[*e_iter]+(num_edges(g)/2)] = flow[*e_iter]; } for(tie(e_iter,e_end)=edges(g); e_iter!=e_end; ++e_iter) put(residual_capacity,*e_iter,speicher[e_index[*e_iter]]); But this is very time inefficient. Does anyone have an idea why the reverse edges do not have the correct residual capacity? Another strange phenomenon is that if I allocate the correct residual capacity only to the reverse edges because the others are correct this change to the residual capacities is not saved. for(tie(e_iter,e_end)=edges(g); e_iter!=e_end; ++e_iter) if(get(e_index,*e_iter) < num_edges(g)/2){ put(residual_capacity,reverse_edge[*e_iter],flow[*e_iter]); Thanks Benjamin

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[bind/function] memory allocation question
by Tim Blechmann 24 Sep '09

24 Sep '09

hi all, i would like to use boost.bind and boost.function in a real-time application, where heap memory allocation is not allowed. according to the docs, boost.function may allocate memory on the heap, but uses a small object optimization, to avoid heap allocation. i'd be curious, if there is a way to figure out, whether heap allocation may occur or not ... i would like to be able to use boost::function objects, initialized by boost::bind, something like: void callme (int some, int args) {} boost::function<void (void)> fn = boost::bind(callme, 1, 2); fn(); thanks, tim -- tim(a)klingt.org http://tim.klingt.org Which is more musical, a truck passing by a factory or a truck passing by a music school? John Cage

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Serialization demo program crashes trying to free an unallocated block
by Jean-Denis Muys 24 Sep '09

24 Sep '09

Hi, Warning: noob inside. I am new to boost, and quite a bit rusty with C+ +, having spent the past few years with other languages. Nonetheless. I downloaded, built and installed Boost 1.40 just fine on Mac OS X 10.6 (Snow Leopard). I set up a XCode 3.2 project to compile and run the demo.cpp program delivered with the Serialization library. It crashes deep inside this line: restore_schedule(new_schedule, filename.c_str()); GDB gives the following error message: malloc: *** error for object 0x1000581a0: pointer being freed was not allocated The stack crawl shows: #0 0x7fff81202ff6 in __kill #1 0x7fff812a4072 in abort #2 0x7fff811bb095 in free #3 0x7fff836031e8 in std::string::reserve #4 0x7fff836032fe in std::string::append #5 0x10028ccac in boost ::archive::text_iarchive_impl<boost::archive::text_iarchive>::load at text_iarchive_impl.ipp:55 #6 0x100024a5e in boost ::archive::load_access::load_primitive<boost::archive::text_iarchive, std::string> at iserializer.hpp:109 #7 0x100024a83 in boost ::archive ::detail::load_non_pointer_type<boost::archive::text_iarchive, std::string>::load_primitive::invoke at iserializer.hpp:332 #8 0x100024aa8 in boost ::archive ::detail::load_non_pointer_type<boost::archive::text_iarchive, std::string>::invoke at iserializer.hpp:417 #9 0x100024acd in boost::archive::load<boost::archive::text_iarchive, std::string> at iserializer.hpp:542 #10 0x100024afe in boost ::archive ::detail ::common_iarchive <boost::archive::text_iarchive>::load_override<std::string> at common_iarchive.hpp:61 #11 0x100024b2b in boost ::archive ::basic_text_iarchive <boost::archive::text_iarchive>::load_override<std::string> at basic_text_iarchive.hpp:62 #12 0x100024b59 in boost ::archive ::text_iarchive_impl <boost::archive::text_iarchive>::load_override<std::string> at text_iarchive.hpp:66 #13 0x100024b8c in boost ::archive ::detail ::interface_iarchive <boost::archive::text_iarchive>::operator>><std::string> at interface_iarchive.hpp:61 #14 0x100024bc3 in boost ::archive ::detail ::interface_iarchive <boost::archive::text_iarchive>::operator&<std::string> at interface_iarchive.hpp:68 #15 0x100026688 in bus_stop_corner::serialize<boost::archive::text_iarchive> at main.cpp: 123 #16 0x1000266c3 in boost::serialization::access::serialize<boost::archive::text_iarchive, bus_stop_corner> at access.hpp:109 and so on... The last frame for which I have source code is #5. There the crashes occurs in the following routine: template<class Archive> BOOST_ARCHIVE_DECL(void) text_iarchive_impl<Archive>::load(std::string &s) { std::size_t size; * this->This() >> size; // skip separating space is.get(); // borland de-allocator fixup #if BOOST_WORKAROUND(_RWSTD_VER, BOOST_TESTED_AT(20101)) if(NULL != s.data()) #endif s.resize(size); // <============== crash here if(0 < size) is.read(&(*s.begin()), size); } In that frame, s is the empty string (its internal buffer points to a 0 byte), and size is 11. Suspecting a bug in OS X std::string class, I checked that the following program works fine: int main() { std::string s; std::size_t size = 11; std::cout << s << std::endl; s.resize(size); std::cout << s << std::endl; } So I tried to follow the stack up tracking the string object to see where and how it was created. I lost track of it in frame #15 on the following line: ar & street1 & street2; Note that this is back to the sample code. I decided to split that line into two lines, and surely now the crashes occurs there: ar & street1; I'm going to go on tracing through that, but maybe this rings a bell with someone, that would save me time... I can post more info if needed. Best regards and thanks, Jean-Denis

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[interprocess] Memory deallocation doesn't seem to work
by Stephan Menzel 24 Sep '09

24 Sep '09

Hi there, I seem to get a strange behavior with 1.40 on windows concerning deallocation. Basically, I have a managed shared memory segment and I allocate several blocks of mem in it typedef boost::interprocess::managed_windows_shared_memory shared_segment; typedef boost::shared_ptr<shared_segment> shared_segment_ptr; ... shared_segment_ptr p = new shared_segment(create_only, buffername.c_str(), begin_size); ... Now I have several allocate_aligned operations: ptr = m_segment->allocate_aligned(static_cast<size_t>(rawsize), 128); Now after a while the segment will have no more room for further blocks. So I delete some of them to gain more room: m_segment->deallocate(raw.get()); (raw is an interprocess::offset_ptr) I debugged into this and there's indeed deallocation functionality called but when I try to allocate afterwards... ptr = m_segment->allocate_aligned(static_cast<size_t>(rawsize), 128); ... I get an interprocess::bad_alloc This makes me believe that either deallocate didn't do a good job or I have to do something after the deallocate() to really make it happen. I looked into the docs for this but there was nothing mentioned so I suppose deallocate() should suffice. I think fragmentation is not really a problem here. We're talking about a few >1MB blocks in a 30MB segment. Plus some administrative overhead. Any ideas what's going on here? Cheers, Stephan

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Boost-regex: Weird behaviour with non-greedy matching operator in regex_replace in boost 1.40?
by Florian Schwarz 24 Sep '09

24 Sep '09

Hi, the non-greedy matching seems to have a weird behaviour (maybe non-determeterministic?) to work if the pattern is preceeded with something. E.g. when I want to get all characters in a string except the last on, if its an 'o', I would use regex matchExpr("(.*?)o?"); So if I write string text("hallo"); regex matchExpr("(.*?)o?"); string valueExpr("$1"); string result; regex_replace(back_inserter(resul), text.begin(), text.end(), matchExpr, valueExpr); cout << "Match \"" << result << "\"" << endl; it will print the expected "hall". If I now use instead string text(" hallo"); regex matchExpr(" (.*?)o?"); it will print "hallo". And for string text("hhallo"); regex matchExpr("h(.*?)o?"); string valueExpr("$1"); regex_replace(back_inserter(resul), text.begin(), text.end(), matchExpr, valueExpr); cout << "Match \"" << result << "\"" << endl; it will print "allo" which seems even more strange to me. I'm using boost1.40 on ubuntu with g++ 4.2.4 To give you a complete example: #include <boost/regex.hpp> #include <iostream> using namespace std; using namespace boost; void test(string& text, regex& matchExpr, string valueExpr){ if (regex_match(text, matchExpr)){ string result; regex_replace(back_inserter(result), text.begin(), text.end(), matchExpr, valueExpr); cerr << "Match \"" << result << "\"" << endl; } } int main(){ { // Test 1 string text("hallo"); regex matchExpr("(.*?)o?"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } { // Test 2 string text(" hallo"); regex matchExpr(" (.*?)o?"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } {// Test 3 string text(" hallo"); regex matchExpr("^ (.*?)o?$"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } { // Test 4 string text("hhallo"); regex matchExpr("h(.*?)o?"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } { // Test 5 string text("hhallo"); regex matchExpr("^h(.*?)o?$"); string valueExpr("$1"); test(text, matchExpr, valueExpr); } } The program will print Match "hall" Match "hallo" Match "hall" Match "allo" Match "hall" I have the following questions: - why does test 1 match the expected "hall" while test 2 matches "hallo" - why does test 1 match the whole string while test 4 matches only a part of it. Many thanks for your help and best regards Florian Schwarz

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Object Pool Usage
by david.weber＠l-3com.com 24 Sep '09

24 Sep '09

So, I'm investigating Object Pools, and I think I'm not getting something. The documentation isn't great, hence the question We have a lot of small objects that we will use throughout our application's lifespan, and I'm trying to see if ObjectPool is a good fit for us. Heck, I'm just trying to look at performance of it in general. So, I have the following code: -------------------------------------------------------------- void testNormal() { common::Timer t; t.start(); for(int i = 0; i < MAX_NUM_TESTS; i++) { testClass t; t.doWork(); } t.stop(); std::cout << "No Pool: Creating " << MAX_NUM_TESTS << " took " << str_cast(t.getTotalElapsedTime()) << std::endl; } void testPool() { common::Timer t; t.start(); boost::object_pool<testClass> pool; for(int i = 0; i < MAX_NUM_TESTS; i++) { testClass::ptr tc = pool.construct(); tc->doWork(); } t.stop(); std::cout << "Pool: Creating " << MAX_NUM_TESTS << " took " << str_cast(t.getTotalElapsedTime()) << std::endl; } int main(int argc, char* argv[]) { testNormal(); testPool(); return 0; } ------------------------------------------------ When run, I am getting: No Pool: Creating 500000 took 00:00:00.187785 Pool: Creating 500000 took 00:00:00.281679 So, I guess I'm not understanding the advantage of the pools. Could someone write/modify my example to make it make more sense? Thanks --dw

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Re: [Boost-users] [Regex] Group of number at line end
by John Maddock 24 Sep '09

24 Sep '09

> i am looking for a regular expression which extracts a group of number > from > the end of a line like the following: > > "This line may contain digits (9) but ends with numbers like 1 2 3 4 5" > > When using a regex like "^(.+)(\\s+(\\d+))+$" I receive > "This line may contain digits (9) but ends with numbers like 1 2 3 4" and > "5". > > Can someone help me? What about: "^(.+)[^\\d\\s](\\s+\\d+)+$" HTH, John.

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boost::filesystem::exists question
by Steven White 23 Sep '09

23 Sep '09

I am working on building a project that relies on OpenSG2 and VR Juggler 2.2 for various reasons between the two I am building Boost 1_37 for the boost co dependency. While working with VR Juggler I noticed the error that boost::filesystem::exists was not defined in libboost_filesystem-xgcc40-mt.dylib. Which I found a little odd. After looking in to it I noticed that it is indeed not defined in either on of my release libs, but was defined in all of the debug libraries. In case I had done something wrong when I compiled boost I started a recompile with the following options. bjam --tool-set=darwin --prefix=$HOME/usr -- build-type=complete -a stage It currently looks like the build will yield the same results. I have a few nm | grep | c++filt below for the new libs. So I have two questions. Is the behavior below normal. If not what might be the cause? nm bin.v2/libs/filesystem/build/darwin-4.0.1/release/link-static/runtime-link-static/threading-multi/libboost_filesystem-xgcc40-mt-s-1_37.a | grep exists | c++filt 000003b0 T boost::filesystem::detail::symbolic_link_exists_api(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) 0002cc00 S __ZN5boost10filesystem6detail24symbolic_link_exists_apiERKSs.eh nm bin.v2/libs/filesystem/build/darwin-4.0.1/debug/link-static/runtime-link-static/threading-multi/libboost_filesystem-xgcc40-mt-sd-1_37.a | grep exists | c++filt 000005a4 T boost::filesystem::detail::symbolic_link_exists_api(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) 00025cf4 S __ZN5boost10filesystem6detail24symbolic_link_exists_apiERKSs.eh 00021fe8 S boost::files nm stage/lib/libboost_filesystem-xgcc40-mt-d-1_37.dylib |grep exists | c++filt 00002822 T boost::filesystem::detail::symbolic_link_exists_api(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) 00004872 T boost::filesystem::exists(boost::filesystem::file_status) volcano boost_1_37_0]$ nm stage/lib/libboost_filesystem-xgcc40-mt-1_37.dylib | grep exists | c++filt 00002010 T boost::filesystem::detail::symbolic_link_exists_api(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)

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[enable_if] Doesn't work for static member functions ?
by Jean-Louis Leroy 23 Sep '09

23 Sep '09

Consider : template<typename U> struct Test { template<typename T> typename enable_if<is_same<T, int>, void>::type test() { cout << "int" << endl; } template<typename T> typename enable_if<is_same<T, char>, void>::type test() { cout << "char" << endl; } }; template<typename T> typename enable_if<is_same<T, int>, void>::type test() { cout << "int" << endl; } template<typename T> typename enable_if<is_same<T, char>, void>::type test() { cout << "char" << endl; } int _tmain(int argc, _TCHAR* argv[]) { test<int>(); test<char>(); Test<int>::test<double>(); // error return 0; } MSVC9 will give a compilation error (see below) where marked. Am I missing something obvious ? Thanks, J-L 1>c:\users\jll\documents\visual studio 2008\projects\boost_1_40_0\libs\rdb\test\test.cpp(325) : error C2143: syntax error : missing ';' before '<' 1> c:\users\jll\documents\visual studio 2008\projects\boost_1_40_0\libs\rdb\test\test.cpp(333) : see reference to class template instantiation 'Test<U>' being compiled 1>c:\users\jll\documents\visual studio 2008\projects\boost_1_40_0\libs\rdb\test\test.cpp(325) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int etc etc etc

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[[value_initialized] when T is const
by Edward Diener 23 Sep '09

23 Sep '09

I like the idea of using value_initialized for a variable to initialize a value to its value intialized value when no initial value is given. But if an initial value is given it does not work if the T is a const type. Was this intended ? Essentially if a variable is a non-const object, one can say, for example: boost::value_initialized<int> data; // data initialized to its value initialized value boost::value_initialized<int> data; boost::get(data) = arg; // data is initialized to value arg For a const value we have: boost::value_initialized<int const> data; // data initialized to its value initialized value but we can not do: boost::value_initialized<int> data; boost::get(data) = arg; // ERROR // try to initialize data to value arg So there is no way to initialize a const T to a value when using boost::value_initialized<T>. This presents a problem in a template class where T can be a const type: template <class T> struct SomeTemplate<T> { boost::value_initialized<T> data; SomeTemplate() { } // always good SomeTemplate(T arg) { boost::get(data) = arg; // FAILS with a const T, // such as if SomeTemplate<int const> is instantiated with any int value // as in 'SomeTemplate<int const> st(4);' } }; In this case boost::value_initialized can not be used. This makes it much less usable in my estimation since the creator of a template class wanting to use boost::value_initialized can only do so if he restricts that template type to a non-const value. If he does not make that restriction then he must go back to initialization by hand and forgo the advantages of value_initialized entirely. It would seem that this limitation could be lifted if the boost::value_initialized template had a constructor which enabled one to initialize the value in cases where initialization to a value initialized state was not desired. Then, despite T being a const type, one could initialize the variable to a specific value.

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[intrusive] list traversing by list_base_hooks
by Tim Blechmann 23 Sep '09

23 Sep '09

hi all, is there a way to traverse a boost::intrusive::list directly from the list_base_hook? i'd like to traverse the list directly from the node something like: my_node: public list_base_hook<> { my_node * previous_node(); my_node * next_node(); }; is it possible to implement something like that? thnx, tim -- tim(a)klingt.org http://tim.klingt.org /"\ ASCII Ribbon Campaign \ / no HTML in email & vCards X no proprietary attachments / \ use open standards

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Calling boost::_mfi::dm on temporaries (e.g. in transform_iterator)
by Sebastian Theophil 23 Sep '09

23 Sep '09

I've encountered a problem when using boost::mem_fn in transform_iterators. In the attached example, I've chained two transform_iterators. The first iterator returns an Obj by value and the second extracts a member of the temporary object. The example shows that the return value is not quite what is expected. boost::mem_fn(&Obj::m_member) returns an int const&. The transform_iterator uses the return value of the UnaryFunction template parameter to initialize his value_type. In the given example, this logic seems too simple. At least if the UnaryFunction is of type boost::_mfi::dm the transform_iterator could do better: If Reference is boost::use_default If UnaryFunction is boost::_mfi::dm && Iterator::value_type is not a reference itself reference = boost::remove_reference( result_of(UnaryFunction) ) Else reference = result_of(UnaryFunction) Else reference = Reference Is this too much of a special case to fix it in the transform_iterator? The same logic would apply to all (unknown) functors that returned references to member variables. In general, the transform_iterator can probably not decide if a reference returned from a UnaryFunction will cease to exist when the temporary is destroyed. It could have been a global object. On the other hand, transform_iterators should work correctly if only boost objects are used, shouldn't they? I'd like to hear what you think, Sebastian #include "boost/iterator/transform_iterator.hpp" #include <vector> struct Obj { Obj(int n) : m_member(n) {} Obj(Obj const& obj) : m_member(obj.m_member) {} ~Obj() { m_member=INT_MIN; } int m_member; }; static Obj GetObjByValue( int n ) { return Obj(n); } void main() { std::vector<int> v(1, 5); int n=*boost::make_transform_iterator( boost::make_transform_iterator( v.begin(), GetObjByValue ), boost::mem_fn(&Obj::m_member) ); _ASSERT(n==INT_MIN); } -- Sebastian Theophil . stheophil(a)think-cell.com Software Engineer think-cell Software GmbH . Invalidenstr. 34 . 10115 Berlin, Germany http://www.think-cell.com . phone +49-30-666473-10 . toll-free (US) +1-800-891-8091 Directors: Dr. Markus Hannebauer, Dr. Arno Schoedl . Amtsgericht Berlin-Charlottenburg, HRB 85229

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[Regex] Group of number at line end
by Reiner Hutsch 23 Sep '09

23 Sep '09

Hallo regex gurus, i am looking for a regular expression which extracts a group of number from the end of a line like the following: "This line may contain digits (9) but ends with numbers like 1 2 3 4 5" When using a regex like "^(.+)(\\s+(\\d+))+$" I receive "This line may contain digits (9) but ends with numbers like 1 2 3 4" and "5". Can someone help me? RHutsch

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wget
by Matthew Galati 23 Sep '09

23 Sep '09

Is there a way to get boost libraries with wget via some ftp server? I am on linux and want to write a script to grab the source directly.

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BGL - read_graphviz and subgraph
by Giuseppe Di Guglielmo 22 Sep '09

22 Sep '09

Dear all, I read on the 'read_graphviz()' page in BGL library doc http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/read_graphviz.html * read_graphviz treats subgraphs as syntactic sugar. It does not reflect subgraphs as actual entities in the BGL. Rather, they are used to shorten some edge definitions as well as to give a subset of all nodes or edges certain properties. For example, the DOT graphs digraph { a -> subgraph {b -> c} -> e } and digraph { a -> b -> e ; a -> c -> e ; b -> c} are equivalent. Is this actually true? Can I read sub-graph from DOT description and obtain a subgraph object? http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/subgraph.html Eventually are subgraph supported by 'read_graphml()' function? http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/read_graphml.html Thanks, G.

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Fwd: Sockets & acceptors
by Wes Alvaro 22 Sep '09

22 Sep '09

I've looked at the examples and tutorials and have destroyed my code trying to get this to work: * I want to connect to a server on a shared port and get a new port number and a unique ID. * The server should accept connections on a shared port and then open a new port to continue communication. * This happens synchronously. Currently, I can connect to the server: tcp::resolver resolver(io); tcp::resolver::query query(server, port); tcp::resolver::iterator endpoint_iterator = resolver.resolve(query); tcp::resolver::iterator end; boost::system::error_code error = boost::asio::error::host_not_found; while (error && endpoint_iterator != end) { serverSocket.close(); serverSocket.connect(*endpoint_iterator++, error); } if (error) { throw boost::system::system_error(error); } int messageSize = sizeof(ident) * 2 + sizeof(int); // ID and port void *message = malloc(messageSize); boost::asio::read(serverSocket, boost::asio::buffer((char *) message, messageSize)); The server code, ripped from the example: tcp::endpoint endpoint( tcp::v4(), this->listenPort ); tcp::acceptor a( io, endpoint ); do { boost::shared_ptr<tcp::socket> sock(new tcp::socket( io )); this->listenSocket = sock; a.accept( *this->listenSocket ); } while(true); As you can see, the server does nothing with the client connection. However, the client reads the 12 bytes as requested in the last line with boost::asio::read. The information received here is junk (to my program) and causes it to crash. What am I doing wrong? What should I be doing? Any help is much appreciated! Thanks, Wes

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Re: [Boost-users] boost zlib problem on linux (works fine onwindows)
by ChristinaDRS 22 Sep '09

22 Sep '09

Hey Steven, Can you post example code to do this? I'm very new to boost! Thanks, Christina >>Try calling flush on the streambuf. >>In Christ, >>Steven Watanabe ChristinaDRS wrote: > This code works fine on Windows, but I get the exception when running in > linux.. any ideas why? The code, how its compiled, and error are below: > > #include <iostream> > #include <sstream> > #include <boost/iostreams/copy.hpp> > #include <boost/iostreams/device/back_inserter.hpp> > #include <boost/iostreams/filter/bzip2.hpp> > #include <boost/iostreams/filter/zlib.hpp> > #include <boost/iostreams/filtering_stream.hpp> > using namespace std; > > int main() > { > string message = "this is a test message!"; > cout << "message: " << message << endl; > string compressed; > boost::iostreams::filtering_streambuf<boost::iostreams::output> > out; > out.push(boost::iostreams::zlib_compressor()); > out.push(boost::iostreams::back_inserter(compressed)); > boost::iostreams::copy(boost::make_iterator_range(message), out); > cout << "compressed message: " << compressed << endl; > > boost::iostreams::filtering_streambuf<boost::iostreams::input> in; > in.push(boost::iostreams::zlib_decompressor()); > in.push(boost::make_iterator_range(compressed)); > string decompressed; > boost::iostreams::copy(in, > boost::iostreams::back_inserter(decompressed)); > cout << "decompressed message: " << decompressed << endl; > } > > > # g++ zlib.cpp zlib_test2.cpp -o zlib_test2 -lz > # ./zlib_test2 > message: this is a test message! > compressed message: > terminate called after throwing an instance of > 'boost::iostreams::zlib_error' > what(): zlib error > Aborted > # > Try calling flush on the streambuf. In Christ, Steven Watanabe _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users -- View this message in context: http://www.nabble.com/Re%3A--Boost-users--boost-zlib-problem-on-linux-%28wo… Sent from the Boost - Users mailing list archive at Nabble.com.

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boost zlib problem on linux (works fine on windows)
by ChristinaDRS 22 Sep '09

22 Sep '09

Hello all, This code works fine on Windows, but I get the exception when running in linux.. any ideas why? The code, how its compiled, and error are below: #include <iostream> #include <sstream> #include <boost/iostreams/copy.hpp> #include <boost/iostreams/device/back_inserter.hpp> #include <boost/iostreams/filter/bzip2.hpp> #include <boost/iostreams/filter/zlib.hpp> #include <boost/iostreams/filtering_stream.hpp> using namespace std; int main() { string message = "this is a test message!"; cout << "message: " << message << endl; string compressed; boost::iostreams::filtering_streambuf<boost::iostreams::output> out; out.push(boost::iostreams::zlib_compressor()); out.push(boost::iostreams::back_inserter(compressed)); boost::iostreams::copy(boost::make_iterator_range(message), out); cout << "compressed message: " << compressed << endl; boost::iostreams::filtering_streambuf<boost::iostreams::input> in; in.push(boost::iostreams::zlib_decompressor()); in.push(boost::make_iterator_range(compressed)); string decompressed; boost::iostreams::copy(in, boost::iostreams::back_inserter(decompressed)); cout << "decompressed message: " << decompressed << endl; } # g++ zlib.cpp zlib_test2.cpp -o zlib_test2 -lz # ./zlib_test2 message: this is a test message! compressed message: terminate called after throwing an instance of 'boost::iostreams::zlib_error' what(): zlib error Aborted # Thanks! Christina -- View this message in context: http://www.nabble.com/boost-zlib-problem-on-linux-%28works-fine-on-windows%… Sent from the Boost - Users mailing list archive at Nabble.com.

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