June 2004 - Boost-users - lists.preview.boost.org

Additional boost resources
by Agoston Bejo 11 Jun '04

11 Jun '04

Hi, do you know about any additional books, tutorials, etc. about boost on the net apart from the boost documentation itself? Any links / titles are welcome. Thx, Gus

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problems using shared_ptr in threads
by Tristan King 11 Jun '04

11 Jun '04

Hi, I'm having trouble getting shared_ptr objects and threads to work in harmony. It may just be that i don't know enough about threads to solve this, but i'm getting undefined behaviour in the code posted at the end of this mail. i'm not worried about the order that the threads run in (as this is just an example of the problem i'm having in a simple multi-threaded web server i'm working on), but it seems like the shared_ptr object may be getting deleted before the last thread gets to execute. i.e. some sample output i'm getting is 0 1 3 4 -572662307 and 1 2 3 3 -572662307 i think i'm probably missing some mutex's or something, but i can't figure it out can anyone give me any pointers on how to get around this problem? thanks in advance --Tristan #include <iostream> #ifdef _MSC_VER #pragma warning(push, 1) #endif #include <boost/thread.hpp> #include <boost/shared_ptr.hpp> #ifdef _MSC_VER #pragma warning(pop) #endif struct simple_thread : public boost::noncopyable { simple_thread( boost::shared_ptr<int> i ) : m_i( i ) {} void operator( )( ) { std::cout << (*m_i) << std::endl; } boost::shared_ptr<int> m_i; }; int main( ) { boost::thread_group threads; for ( int i = 0 ; i < 5 ; ++i ) { boost::shared_ptr<int> p( new int(i) ); simple_thread trd( p ); threads.create_thread( boost::ref( trd ) ); }; threads.join_all( ); return 0; }

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link problems with boost_regex on Solaris
by Drew Lowry 09 Jun '04

09 Jun '04

I'm using boost_regex 1.28.0 with STLport 4.5.3 on Solaris using Forte compiler. When I build with -g option, it fails at linkage with the following errors ild: (undefined symbol) boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1(const boost::detail::allocator<__type_1>&) -- referenced in the text segment of ../../../../packages/boost_1_28_0/sparc-solaris/libboost_regex_mt.a(OhCenAP7d5aN-_Bfr3wh.o) ild: (undefined symbol) boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1(const boost::detail::allocator<__type_1>&) -- referenced in the text segment of ../../../../packages/boost_1_28_0/sparc-solaris/libboost_regex_mt.a(J-U5NXbbfexb9iPLelyN.o) ild: (undefined symbol) boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1(const boost::detail::allocator<__type_1>&) -- referenced in the text segment of ../../../../packages/boost_1_28_0/sparc-solaris/libboost_regex_mt.a(5cVinizdRsfQ1ujqbKlp.o) ild: (undefined symbol) boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1(const boost::detail::allocator<__type_1>&) -- referenced in the text segment of ../../../../packages/boost_1_28_0/sparc-solaris/libboost_regex_mt.a(TbU7jVI0o3rCSz-c48HV.o) ild: (undefined symbol) boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1(const boost::detail::allocator<__type_1>&) -- referenced in the text segment of ../../../../packages/boost_1_28_0/sparc-solaris/libboost_regex_mt.a(Zi2bUcR97vUxCHzFzV0a.o) ild: (undefined symbol) boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1(const boost::detail::allocator<__type_1>&) -- referenced in the text segment of ../../../../packages/boost_1_28_0/sparc-solaris/libboost_regex_mt.a(aTM7t-gA2lwhiyP5RH3P.o) ild: (undefined symbol) boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1(const boost::detail::allocator<__type_1>&) -- referenced in the text segment of ../../../../packages/boost_1_28_0/sparc-solaris/libboost_regex_mt.a(OkRWOOTWnnv97gH0a9t_.o) ild: (undefined symbol) boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1(const boost::detail::allocator<__type_1>&) -- referenced in the text segment of ../../../../packages/boost_1_28_0/sparc-solaris/libboost_regex_mt.a(hKZggW9H89qzPd1td_2e.o) ild: (undefined symbol) boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1(const boost::detail::allocator<__type_1>&) -- referenced in the text segment of ../../../engine/lib/sparc-solaris/ Any idea what's going on? Everything works fine without -g option. ____________________________________________________________ Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now http://uk.messenger.yahoo.com/download/index.html

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Problem compiling Threading lib on Linux
by Damien McGivern 09 Jun '04

09 Jun '04

Hi, I've been developing some code on Windows using Boost threads which works fine. I'm porting it to Linux and am having problems compiling the Boost Threading library. I'm running Linux Mandrake 10 Community Edition and have attached the output I get when running bjam. I don't actually have bjam included in the PATH enviroment variable as I'm not sure how to do this in Linux so I just copied the bjam exe into the thread build directory - I doubt it but could this be the cause of the problem? Any help on how to solve this would be much appreciated. Cheers Damien ____________________________________________________________ Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now http://uk.messenger.yahoo.com/download/index.html [damien@tux build]$ ./bjam "-sTOOLS=gcc" ...patience... ...found 367 targets... ...updating 39 targets... MkDir1 ../../../libs/thread/build/bin-stage MkDir1 ../../../bin MkDir1 ../../../bin/boost MkDir1 ../../../bin/boost/libs MkDir1 ../../../bin/boost/libs/thread MkDir1 ../../../bin/boost/libs/thread/build MkDir1 ../../../bin/boost/libs/thread/build/libboost_thread.so MkDir1 ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc MkDir1 ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug MkDir1 ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true MkDir1 ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/condition.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/mutex.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/recursive_mutex.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/thread.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/tss.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/xtime.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/once.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/exceptions.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/threadmon.o gcc-Link-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31d.so ln: creating symbolic link `../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31d.so' to `libboost_thread-gcc-mt-d-1_31d.so.1.31.0': Operation not permitted LD_LIBRARY_PATH=../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi:$LD_LIBRARY_PATH export LD_LIBRARY_PATH g++ -g -pthread -fPIC -shared -o "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31d.so.1.31.0" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/condition.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/mutex.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/recursive_mutex.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/thread.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/tss.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/xtime.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/once.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/exceptions.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/threadmon.o" -lrt -Wl,-rpath-link,. -Wl,-soname,libboost_thread-gcc-mt-d-1_31d.so.1.31.0 ln -fs "libboost_thread-gcc-mt-d-1_31d.so.1.31.0" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31d.so" ...failed gcc-Link-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31d.so... ...skipped <@boost!libs!thread!build!bin-stage>libboost_thread-gcc-mt-d-1_31d.so for lack of <@boost!libs!thread!build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi>libboost_thread-gcc-mt-d-1_31d.so... FileClone ../../../libs/thread/build/bin-stage/libboost_thread-gcc-mt-d-1_31d.so.1.31.0 MkDir1 ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release MkDir1 ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true MkDir1 ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/condition.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/mutex.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/recursive_mutex.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/thread.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/tss.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/xtime.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/once.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/exceptions.o gcc-C++-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/threadmon.o gcc-Link-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-1_31.so ln: creating symbolic link `../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-1_31.so' to `libboost_thread-gcc-mt-1_31.so.1.31.0': Operation not permitted LD_LIBRARY_PATH=../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi:$LD_LIBRARY_PATH export LD_LIBRARY_PATH g++ -pthread -s -fPIC -shared -o "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-1_31.so.1.31.0" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/condition.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/mutex.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/recursive_mutex.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/thread.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/tss.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/xtime.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/once.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/exceptions.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/threadmon.o" -lrt -Wl,-rpath-link,. -Wl,-soname,libboost_thread-gcc-mt-1_31.so.1.31.0 ln -fs "libboost_thread-gcc-mt-1_31.so.1.31.0" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-1_31.so" ...failed gcc-Link-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-1_31.so... ...skipped <@boost!libs!thread!build!bin-stage>libboost_thread-gcc-mt-1_31.so for lack of <@boost!libs!thread!build/libboost_thread.so/gcc/release/shared-linkable-true/threading-multi>libboost_thread-gcc-mt-1_31.so... FileClone ../../../libs/thread/build/bin-stage/libboost_thread-gcc-mt-1_31.so.1.31.0 gcc-Link-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31.so ln: creating symbolic link `../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31.so' to `libboost_thread-gcc-mt-d-1_31.so.1.31.0': Operation not permitted LD_LIBRARY_PATH=../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi:$LD_LIBRARY_PATH export LD_LIBRARY_PATH g++ -g -pthread -fPIC -shared -o "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31.so.1.31.0" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/condition.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/mutex.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/recursive_mutex.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/thread.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/tss.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/xtime.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/once.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/exceptions.o" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/threadmon.o" -lrt -Wl,-rpath-link,. -Wl,-soname,libboost_thread-gcc-mt-d-1_31.so.1.31.0 ln -fs "libboost_thread-gcc-mt-d-1_31.so.1.31.0" "../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31.so" ...failed gcc-Link-action ../../../bin/boost/libs/thread/build/libboost_thread.so/gcc/debug/shared-linkable-true/threading-multi/libboost_thread-gcc-mt-d-1_31.so... ...failed updating 3 targets... ...skipped 2 targets... ...updated 34 targets...

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BGL: Internal Compiler Error with VC++ 7.1
by Finnegan Southey 09 Jun '04

09 Jun '04

Hi, I'm getting the following error trying to iterate over adjacent vertices in boost_1_31 with VC++ 7.1: c:\boost_1_31_0\boost\mpl\aux_\preprocessed\plain\apply.hpp(50) : fatal error C1001: INTERNAL COMPILER ERROR (compiler file 'msc1.cpp', line 2701) I have noticed other similar problems reported in the list archive along with a request for a short example. Any advice would be appreciated. The following example demonstrates the problem, sufficiently briefly, I hope. -------------- CUT ------------------------------------------- #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> typedef boost::property<boost::edge_weight_t, int> LocationEdgeProperty; typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::no_property, LocationEdgeProperty> LocationGraph; typedef boost::graph_traits<LocationGraph>::vertex_descriptor VertexDescriptor; typedef boost::graph_traits<LocationGraph>::adjacency_iterator AdjacencyIterator; void test() { LocationGraph graph; VertexDescriptor current = 0; std::pair<AdjacencyIterator, AdjacencyIterator> neighbourRange = boost::adjacent_vertices(current, graph); // ICE here for (; neighbourRange.first != neighbourRange.second; neighbourRange.first++) { } } -------------- CUT ------------------------------------------- Regards, Finnegan

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Query re a Boost calculus library
by Andy Elvey 08 Jun '04

08 Jun '04

Hi everyone - I'm a newcomer to this list (but have used Boost Spirit for a long time). I've looked through the various Boost libraries and have noticed that there seems to be one area of mathematics that isn't covered by the existing libraries : calculus (derivatives, integrals). So, my question is - is there a reason for this, or is it just that a suitable library for inclusion hasn't appeared yet? ( I'm aware of a possible one that could be put forward as a candidate, but I don't know if it's "OK" for me to suggest a library ). Many thanks in advance. - Andy

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RE: [Boost-users] enable_if question
by Hurd, Matthew 08 Jun '04

08 Jun '04

D'oh. Thanks Jaakko. Regards, Matt Hurd. _______________ Matt Hurd +61.2.8226.5029 hurdm(a)sig.com Susquehanna _______________ > bounces(a)lists.boost.org] On Behalf Of jajarvi > Subject: Re: [Boost-users] enable_if question > > On Jun 7, 2004, at 7:11 PM, Hurd, Matthew wrote: > > > > SFINAE does not kick in, because the condition > (is_arithmetic<std::string>::value) is not dependent on any template > arguments. > > Cheers, Jaakko > IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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enable_if question
by Hurd, Matthew 08 Jun '04

08 Jun '04

I'm just trying to play with enable_if and learn something. I just mean to replace this template method's code: template< bool > void exchange_code( boost::call_traits<std::string>::param_type new_exchange_code ) { if ( boost::is_arithmetic<std::string>::value ) { lock lk(guard_ ); exchange_code<false>( new_exchange_code); } else { exchange_code<false>( new_exchange_code); } } With this: template< bool > typename boost::enable_if_c< boost::is_arithmetic<std::string>::value, void >::type exchange_code( boost::call_traits<std::string>::param_type new_exchange_code ) { lock lk(guard_ ); exchange_code<false>( new_exchange_code); } template< bool > typename boost::disable_if_c< boost::is_arithmetic<std::string>::value , void >::type exchange_code( boost::call_traits<std::string>::param_type new_exchange_code ) { exchange_code<false>( new_exchange_code); } Forget the relevance of the is_arithmetic bit, I use my own needs_lock thingo. For a start: The compiler correctly identifies that ::type is not a member, but SFINAE does not seem to kick in if I'm reading it correctly. ____________________ c:\source\matt\trading_engine\controller\instrument.hpp(66) : error C2039: 'type' : is not a member of 'boost::enable_if_c<B,T>' with [ B=false, T=void ] c:\source\matt\trading_engine\controller\instrument.hpp(143) : see reference to class template instantiation 'te::instrument<S>' being compiled ____________________ template< bool > typename boost::disable_if_c< boost::is_arithmetic<std::string>::value , void >::type exchange_code( boost::call_traits<std::string>::param_type new_exchange_code ) { exchange_code<false>( new_exchange_code); } Is fine... Flipping the conditions round by changing to is_arithmetic< int > flips the failures around. Same issue with the extra parameter approach: template< bool > void exchange_code( boost::call_traits<std::string>::param_type new_exchange_code, typename boost::enable_if_c< boost::is_arithmetic<int>::value, void >::type* dummy = 0 ) { lock lk(guard_ ); exchange_code<false>( new_exchange_code); } template< bool > void exchange_code( boost::call_traits<std::string>::param_type new_exchange_code, typename boost::disable_if_c< boost::is_arithmetic<int>::value , void >::type* dummy = 0 ) { exchange_code<false>( new_exchange_code); } Is SFINAE meant to work in this way with member templates with enable_if, vc7.1 and boost 1.31? Something simple is probably escaping me... Any thoughts? Regards, Matt Hurd. _______________ Matt Hurd +61.2.8226.5029 hurdm(a)sig.com Susquehanna _______________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

2 1

Looking for more advanced type_traits-like functionality
by Agoston Bejo 08 Jun '04

08 Jun '04

Hi, I have took a look at some parts of the boost library, but I couldn't find what I want, and that is something like this: How can I determine if a type T has such and such member? It would look like something like this: has_member<T, paint>::result (true if T::paint() exists) has_member<T, m_size>::result (true if T::m_size exists) The closest to this I could find is boost::type_traits but that does not provide this functionality. Thx, Gus

4 6

boost::bind and boost::function fail at run-time in managed c++
by Russell Hind 08 Jun '04

08 Jun '04

Compiling the following code with /CLR on, results in an empty function exception at run-time. If you un-comment the #pragma unmanaged to get native compilation, it runs fine. Thanks Russell #include "stdafx.h" #using <mscorlib.dll> //#pragma unmanaged #include <boost/bind.hpp> #include <boost/function.hpp> class Test_c { public: void test(void) { } }; int main() { Test_c Test; boost::function<void (void)> f(boost::bind(&Test_c::test, &Test)); f(); return 0; }

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