March 2010 - Boost-users - lists.preview.boost.org

[concept]
by er 22 Mar '10

22 Mar '10

Hello, With gcc version 4.4.1 (Ubuntu 4.4.1-4ubuntu9). This BOOST_CONCEPT_ASSERT((boost::SinglePassRangeConcept<boost::array<int,8u>>)); is greeted with the warning below, which is annoying. It appears that the reference T& template<typename T> struct SinglePassRangeConcept { private: T& m_range; }; is causing it, but can be eliminated by replacing T& by static T& m_range. Perhaps there is a good reason for T& rather than static T& so I stopped short of putting a request in trac. Please advise. Thanks. ../../Reposetories/boost/trunk/boost/concept/detail/has_constraints.hpp|42|instantiated from ‘const bool boost::concepts::not_satisfied<boost::SinglePassRangeConcept<boost::array<int, 8u> > >::value’| ../../Reposetories/boost/trunk/boost/concept/detail/has_constraints.hpp|45|instantiated from ‘boost::concepts::not_satisfied<boost::SinglePassRangeConcept<boost::array<int, 8u> > >’| ../../Reposetories/boost/trunk/boost/mpl/if.hpp|67|instantiated from ‘boost::mpl::if_<boost::concepts::not_satisfied<boost::SinglePassRangeConcept<boost::array<int, 8u> > >, boost::concepts::constraint<boost::SinglePassRangeConcept<boost::array<int, 8u> > >, boost::concepts::requirement<boost::concepts::failed************ boost::SinglePassRangeConcept<boost::array<int, 8u> >::************> >’| ../../Reposetories/boost/trunk/boost/concept/detail/general.hpp|20|instantiated from ‘boost::concepts::requirement_<void (*)(boost::SinglePassRangeConcept<boost::array<int, 8u> >)>’| /home/me/Reposetories/boost/sanbox/statistics/detail/assign/libs/assign/example/chain.cpp|42|instantiated from here| ../../Reposetories/boost/trunk/boost/range/concepts.hpp|209|warning: non-static reference ‘boost::array<int, 8u>& boost::SinglePassRangeConcept<boost::array<int, 8u> >::m_range’ in class without a constructor| /home/me/Reposetories/boost/sanbox/statistics/detail/assign/libs/assign/example/chain.cpp||In function ‘void example_ch

2 2

[proto] need explanation in implementing distributive law
by Kim Kuen Tang 22 Mar '10

22 Mar '10

Hi all, i would like to implement a grammar that transform a*(b+c) to a*b+a*c where a,b and c are terminals. The implementation of this grammar is straightforward and should compile. However i got errors that i dont understand. Below is the code that reproduces the errors. Thanks for any help, Kim # include <boost/cstdlib.hpp> # include <boost/proto/proto.hpp> # include <boost/fusion/container/list/cons.hpp> # include <boost/proto/tags.hpp> # include <boost/proto/make_expr.hpp> # define PRECISION_MAKE_tag(name) \ struct name \ { \ friend std::ostream& operator<< (std::ostream& s, name const&) \ { \ return s<< #name; \ } \ }; # define PRECISION_MAKE_terminal(name) \ proto::terminal< tag::name >::type const name = {{}} namespace proto = boost::proto; namespace tag{ PRECISION_MAKE_tag(a); PRECISION_MAKE_tag(b); PRECISION_MAKE_tag(c); } namespace mpl = boost::mpl; namespace fusion = boost::fusion; using proto::_; struct DistributiveLaw : proto::or_< proto::when< proto::multiplies< proto::terminal< _ > , proto::plus< _, _ > > , proto::plus< proto::multiplies<proto::_left,proto::_left(proto::_right)> , proto::multiplies<proto::_left,proto::_right(proto::_right)> //, proto::_right(proto::_right) >( proto::multiplies<proto::_left,proto::_left(proto::_right)> (proto::_left,proto::_left(proto::_right)) , proto::multiplies<proto::_left,proto::_right(proto::_right)> (proto::_left,proto::_right(proto::_right)) //, proto::_right(proto::_right) ) > , proto::otherwise<proto::nary_expr<_, proto::vararg<DistributiveLaw> > > > {}; PRECISION_MAKE_terminal(a); PRECISION_MAKE_terminal(b); PRECISION_MAKE_terminal(c); # undef PRECISION_MAKE_tag # undef PRECISION_MAKE_terminal int main() { proto::display_expr(a*(b+c)); proto::display_expr(DistributiveLaw()( a*(b+c) )); return boost::exit_success; }

3 4

boost::bind and max #args
by Andrej van der Zee 22 Mar '10

22 Mar '10

Hi, I need to call boost::bind with 10 arguments. I believe that the maximum is nine. Is there a way to increase this? Thank you, Andrej

4 4

Re: [Boost-users] [program-options] static linked example segfaults for exception
by Neetu Garg 22 Mar '10

22 Mar '10

Hi, Can I please get some input on this issue. Thanks for your help Regards, NG ----- Original Message ---- From: Neetu Garg <garg_neetu(a)yahoo.com> To: boost-users(a)lists.boost.org Sent: Fri, March 19, 2010 11:08:43 AM Subject: Re: program option library segfaults for exception I did little more digging into the issue If I compile and link following sample on Linux dynamically using following command g++ -c -I. -I/usr/local/include/boost-1_38 -I/usr/include testprogramoptions.cpp -o testprogramoptions.o g++ testprogramoptions.o -static-libgcc -L/u/neetug/Projects/performance/perfstat_cluster/lib -lboost_program_options-gcc41-mt -lpthread -o testprogramoptions [root@perf-tools-7 src]# ./testprogramoptions --o ERROR unknown option o ERROR Error while parsing CLI options Exiting Here "--o" is unknown option ======================================================================= If I compile and link following sample on Linux statically using following command g++ -c -I. -I/usr/local/include/boost-1_38 -I/usr/include testprogramoptions.cpp -o testprogramoptions.o g++ testprogramoptions.o -static-libgcc -Wl,-Bstatic -L/u/neetug/Projects/performance/perfstat_cluster/lib -lboost_program_options-gcc41-mt -lpthread -o testprogramoptions [root@perf-tools-7 src]# ./testprogramoptions --o Aborted Here "--o" is unknown option ======================================================================== I am not sure why the behavior is different with different linking option why I am not getting exception for static linking. Really appreciate any help in this issue. Here in the test program #include <iostream> #include <boost/program_options.hpp> namespace boostOptions = boost::program_options; using namespace std; int main(int argCount, char* argList[]) { try { boostOptions::options_description commonOpt("Options (common)"); commonOpt.add_options() ("help,h", "Produce help message.") ("version,v", "Prints perfstat version, and supported ONTAP versions.") ; boostOptions::options_description runModeOpt("Options ('run' mode)"); runModeOpt.add_options() ("clusterinfo", boostOptions::value<string>(), "cluster IP.") ("sample-interval", boostOptions::value<int>(), "Specifies statit/sysstat frequency") ; boostOptions::positional_options_description posOption; posOption.add("clusterinfo", -1); boostOptions::options_description allOptDesc("Allowed options :"); allOptDesc.add(commonOpt).add(runModeOpt); boostOptions::variables_map varMap; boostOptions::store(boostOptions::command_line_parser(argCount, argList). options(allOptDesc).positional(posOption).run(), varMap); boostOptions::notify(varMap); } catch(std::exception &e) { cout << "ERROR " << e.what() << "\n"; cout << "ERROR " << "Error while parsing CLI options Exiting" << "\n"; exit(0); } catch(...) { cout << "ERROR 1 " << "\n"; cout << "ERROR 1 " << "Error while parsing CLI options Exiting" << "\n"; exit(0); } } Regards, NG ----- Original Message ---- From: Neetu Garg <garg_neetu(a)yahoo.com> To: boost-users(a)lists.boost.org Sent: Wed, March 17, 2010 1:17:07 PM Subject: program option library segfaults for exception Sorry for the duplicate post, I think my message posted under different conversation. Hi, I have application that is using boost program option library. If I provide unknown option via CLI it should throw exception. The library is statically linked on windows and Linux environment. It works fine on windows platform I do get exception for unknown CLI option. On Linux platform I get "segfault" in place of exception for unknown CLI option. It is s a multi-threaded application and it also uses boost thread library. Application does throw exception on Linux also if I link dynamically. I am using following flags to link the library statically: LDFLAGS= -fexceptions -static-libgcc -Wl,-static -L/usr/lib -lboost_program_options-gcc41-mt -lboost_filesystem-gcc41-mt -lboost_thread-gcc41-mt -lboost_system-gcc41-mt -lnet7ssh -lbotan -ltar -lz -lrt -lpthread I am using following version of gcc: # g++ --version g++ (GCC) 4.1.1 Copyright (C) 2006 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Here is the core dump for the segfault: (gdb) backtrace #0 __gnu_internal::get_global () at /usr/software/src/gcc-4.1.1/libstdc++-v3/libsupc++/eh_globals.cc:58 #1 0x082c0f67 in __cxa_get_globals () at /usr/software/src/gcc-4.1.1/libstdc++-v3/libsupc++/eh_globals.cc:71 #2 0x082c0b3f in __cxa_allocate_exception (thrown_size=32) at /usr/software/src/gcc-4.1.1/libstdc++-v3/libsupc++/eh_alloc.cc:154 #3 0x080a71f8 in boost::program_options::detail::cmdline::finish_option () #4 0x080a77eb in boost::program_options::detail::cmdline::run () #5 0x0806f3aa in boost::program_options::basic_command_line_parser<char>::run () #6 0x080660e9 in CLIHandler::collectCLIOptions () #7 0x0808a0d1 in perfstat::runPerfstat () #8 0x0808af3d in main () Current language: auto; currently c++ Appreciate your help Regards, NG

3 2

Compiling for Solaris X64
by Iskandar Prins 22 Mar '10

22 Mar '10

Hi All, I need some help with compiling boost for solaris x64. When I try to compile the bjam, I get a x86 version of bjam and boost, any idea what setting/flag I need to use on bjam? Regards, Iskandar Prins iprins(a)alphabay.nl

2 4

[serialization] Seek in a binary archive
by Damien R 22 Mar '10

22 Mar '10

Hi, I save fixed size objects in a binary archive and when I load the binary archive, I try to seek at a specific position. To do that I call istream.seekg() but the problem is that boost::serialization get the rdbuf of the input stream, so the seek does not work. I would like to know whether I have to create a class like basic_binary_iprimitive or whether there is a better alternative. Thanks,

1 0

Re: [Boost-users] [proto] generation of adaptive precision floating-point geometric predicates
by Kim Kuen Tang 22 Mar '10

22 Mar '10

Hi Andrew, just my thoughts on this chat. Andrew Durward schrieb: > > The central concept is that for any expression (a # b) where # is {+, -, *}, > the result can be expressed as (x + y) where x is the floating-point How about transform the expression a+b to sum_approx(a,b)+sum_diff(a,b) instead to fusion::cons<sum_approx(a,b),fusion::cons<sum_diff(a,b)> > ? The advantage of this approach is that you still get an ast where childs are held in terminal (instead in cons). > approximation of (a # b), and y is an error term whose value can also be > computed as a floating-point value. > > In toying with proto, I've been able to transform simple expressions > successfully but I can't seem to figure out how to define a grammar that > will handle arbitrary combinations of {+, -, *} recursively. Here's what > I've got so far: > > struct sum_approx{/* */}; > struct sum_error{/* */}; > > struct diff_approx{/* */}; > struct diff_error{/* */}; > > struct prod_approx{/* */}; > struct prod_error{/* */}; > > struct Transform : > proto::or_< > proto::when< > proto::plus< proto::terminal< _ >, proto::terminal< _ > > > , fusion::cons< > proto::_make_function( > sum_approx() > , proto::_left > , proto::_right > ) I dont see the meaning behind this step. If you use proto::_make_function you create a child in the ast, but you put this child in a fusion::cons. > , fusion::cons< > proto::_make_function( > sum_error() > , proto::_left > , proto::_right > ) > > > >() > > > // ... similar substitutions for minus and multiplies > > > {}; > > So the expression (a + b) yields the sequence: > sum_approx(a,b) > sum_error(a,b) > > Here's where I'm stuck. In the case of the expression (a + b)*(c - d), the > addition and subtraction should be replaced by the appropriate sequences > before the multiplication gets expanded to yield the final sequence: > prod_approx( sum_approx(a,b), diff_approx(c,d) ) > prod_error( sum_approx(a,b), diff_approx(c,d) ) > prod_approx( sum_approx(a,b), diff_error(c,d) ) > prod_error( sum_approx(a,b), diff_error(c,d) ) > prod_approx( sum_error(a,b), diff_approx(c,d) ) > prod_error( sum_error(a,b), diff_approx(c,d) ) > prod_approx( sum_error(a,b), diff_error(c,d) ) > prod_error( sum_error(a,b), diff_error(c,d) ) Are you sure that you want to get a sequence of expression instead an ast. In case you really want to get a sequence you can use proto::tag::comma to separate your child. > Obviously I need a recursive transform here but I'm not sure how to pass it > the sequences generated by both the left and right subtrees. > > Cheers, Kim Here is a toy project. Hth. # include <boost/cstdlib.hpp> # include <boost/proto/proto.hpp> # include <boost/fusion/container/list/cons.hpp> # include <boost/proto/tags.hpp> # include <boost/proto/make_expr.hpp> # define PRECISION_MAKE_tag(name) \ struct name \ { \ friend std::ostream& operator<< (std::ostream& s, name const&) \ { \ return s<< #name; \ } \ }; # define PRECISION_MAKE_terminal(name) \ proto::terminal< tag::name >::type const name = {{}} namespace proto = boost::proto; namespace tag{ PRECISION_MAKE_tag(a); PRECISION_MAKE_tag(b); PRECISION_MAKE_tag(c); PRECISION_MAKE_tag(d); PRECISION_MAKE_tag(sum_approx); PRECISION_MAKE_tag(sum_error); PRECISION_MAKE_tag(diff_approx); PRECISION_MAKE_tag(diff_error); } namespace mpl = boost::mpl; namespace fusion = boost::fusion; using proto::_; struct transform { BOOST_PROTO_CALLABLE() template<typename Sig> struct result; template<typename This,typename A0,typename A1> struct result<This(proto::tag::plus const,A0,A1)> : proto::result_of::make_expr< proto::tag::plus , typename proto::result_of::make_expr< proto::tag::function ,tag::sum_approx, A0, A1 >::type , typename proto::result_of::make_expr< proto::tag::function ,tag::sum_error, A0, A1 >::type > {}; template<typename This,typename A0,typename A1> struct result<This(proto::tag::minus const,A0,A1)> : proto::result_of::make_expr< proto::tag::minus, A0, A1 > {}; template<typename A0,typename A1> typename result<transform(proto::tag::plus const ,A0 const&, A1 const&)>::type operator()(proto::tag::plus const ,A0 const& a0,A1 const& a1) const { return proto::make_expr<proto::tag::plus>( proto::make_expr<proto::tag::function>( tag::sum_approx() , boost::ref(a0) , boost::ref(a1)) ,proto::make_expr<proto::tag::function>( tag::sum_error() , boost::ref(a0) , boost::ref(a1)) ); //return proto::make_expr<proto::tag::plus>(boost::ref(a0), boost::ref(a1)); }; template<typename A0, typename A1> typename result<transform(proto::tag::minus const ,A0 const&, A1 const&)>::type operator()(proto::tag::minus const ,A0 const& a0, A1 const& a1) const { return proto::make_expr<proto::tag::minus>(boost::ref(a0), boost::ref(a1)); }; }; struct Transform : proto::or_< proto::when< proto::plus< proto::terminal< _ >, proto::terminal< _ > > , transform( proto::tag::plus() , proto::_value(proto::_left) , proto::_value(proto::_right) ) > ,proto::when< proto::minus< proto::terminal< _ >, proto::terminal< _ > > , transform( proto::tag::minus() , proto::_value(proto::_left) , proto::_value(proto::_right) ) > , proto::otherwise<proto::nary_expr<_, proto::vararg<Transform> > > > {}; PRECISION_MAKE_terminal(a); PRECISION_MAKE_terminal(b); PRECISION_MAKE_terminal(c); PRECISION_MAKE_terminal(d); # undef PRECISION_MAKE_tag # undef PRECISION_MAKE_terminal int main() { proto::display_expr(a+b); BOOST_AUTO(expr, Transform()( (a+b)*(c-d) ) ); proto::display_expr(expr); return boost::exit_success; }

2 1

Re: [Boost-users] [proto] generation of adaptive precision floating-point geometric predicates
by Manjunath Kudlur 22 Mar '10

22 Mar '10

> Here's where I'm stuck. In the case of the expression (a + b)*(c - d), the > addition and subtraction should be replaced by the appropriate sequences > before the multiplication gets expanded to yield the final sequence: See if the following works for you. I try to replace a # b with sum(#_approx(a,b), #_error(a,b)). The display_expr looked correct, but I didn't check very carefully. #include <boost/proto/proto.hpp> #include <iostream> namespace proto = boost::proto; using proto::_; unsigned ids = 0; struct var { unsigned id; var() { id = ids++; } friend std::ostream &operator<<(std::ostream &s, var v) { s << "V" << v.id; return s; } }; struct sum_approx { friend std::ostream &operator<<(std::ostream &s, sum_approx) { s << "sum_approx"; return s; } }; struct sum_error { friend std::ostream &operator<<(std::ostream &s, sum_error) { s << "sum_error"; return s; } }; struct diff_approx { friend std::ostream &operator<<(std::ostream &s, diff_approx) { s << "diff_approx"; return s; } }; struct diff_error { friend std::ostream &operator<<(std::ostream &s, diff_error) { s << "diff_error"; return s; } }; struct prod_approx { friend std::ostream &operator<<(std::ostream &s, prod_approx) { s << "prod_approx"; return s; } }; struct prod_error { friend std::ostream &operator<<(std::ostream &s, prod_error) { s << "prod_error"; return s; } }; struct sum { friend std::ostream &operator<<(std::ostream &s, sum) { s << "sum"; return s; } }; struct grammar : proto::or_< proto::when<proto::plus<grammar, grammar>, proto::_make_function(sum(), proto::_make_function(sum_approx(), grammar(proto::_left), grammar(proto::_right)), proto::_make_function(sum_error(), grammar(proto::_left), grammar(proto::_right)))> ,proto::when<proto::minus<grammar, grammar>, proto::_make_function(sum(), proto::_make_function(diff_approx(), grammar(proto::_left), grammar(proto::_right)), proto::_make_function(diff_error(), grammar(proto::_left), grammar(proto::_right)))> ,proto::when<proto::multiplies<grammar, grammar>, proto::_make_function(sum(), proto::_make_function(prod_approx(), grammar(proto::_left), grammar(proto::_right)), proto::_make_function(prod_error(), grammar(proto::_left), grammar(proto::_right)))> , proto::terminal<var> > {}; typedef proto::terminal<var>::type Var; int main() { Var a, b, c, d; proto::display_expr(grammar()( (a+b)*(c-d) )); }

2 1

Will asio::ip::tcp::socket::read let me read all my data even if remote end is connected?
by Sean McAllister 22 Mar '10

22 Mar '10

Looking at the documentation for this function: http://www.boost.org/doc/libs/1_37_0/doc/html/boost_asio/reference/basic_st… I'm not entirely clear whether it will do what I want. Basically I'm going to be having a server send blocks of signal data (of unknown duration or length). I'd like the client to be able to read chunks of that until the remote end closes. So right now my API has the user pass in a memory buffer to fill along with a size and I repeatedly call socket::read to fill it up. What I'm curious about is if the server doesn't send a full block for the last block, and then closes the connection. Will this function still return whatever data it was able to read and then throw an exception on the next read? Or will it throw an exception on that last read, rendering the last bit of data inaccesible? Sean

2 4

IOService.run()
by Iskandar Prins 22 Mar '10

22 Mar '10

Hi, I have a question regarding the asio::deadline_timer , it seems I need to run the ioservice.run() all the time in order to update the timer, which is seems undesirable. Any idea how I can just start the timer and wait for the callback instead? Regards, Iskandar Prins IT Software Developer Alphabay Capital B.V. Singel 540 1017AZ Amsterdam Tel: +31 (0)20 755 9642 Fax: +31 (0)20 755 9601 iprins(a)alphabay.nl

3 3