- Boost - lists.boost.org

Any Chances for Boost Stable?
by Artyom 21 Jan '10

21 Jan '10

Hello, This mail is rather discussion of possible future Boost policy rather then concrete features it provides. Is there any chance for Stable Boost version? --------------------------------------------- What do I mean stable? Stable as Qt4, stable as STL Port, or STL. Boost is one of the greatest platforms for development of bleeding edge technologies. Like Boost.Asio is one of the greatest Asynchronous API libraries. On the other hand, this library is extremely unstable: each release breaks compatibility with previous one! When I compile a program or library that uses STL I expect that it would continue to work as long as compiler keeps table ABI (GCC - for years). I can compile great GUI application with Qt and expect from it to work for years and be sure that core Qt library includes updates, bug fixes and so. I can't do it with Boost! -------------------------------------------------------- Is there any chance to create a stable Boost branch that includes: - All libraries included in Tr1 - Various other stable libraries. This branch would keep: stable API and ABI, It may include additional libraries and features as long as they do not break API/ABI. Adopt the code such that different changes would not break ABI. For example, if shared_ptr on specific platform uses mutex or atomic counter, it would not be changed withing release because of new supported feature -- meaning config.hpp should be recompiled similarly as it done with autotools. Adopt pimpl policies of Qt to make sure that classes can be easily extended without breaking them. ------------------------------------ I know that this is lot of work and this is totally different from current Boost policy. But Boost should not be only experimental library... It should be as stable as STLPort or STL. -------------------------------- Do we need Boost.Stable branch? -------------------------------- Artyom

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Boost is complicated. This forum too. (please help about accumulators)
by Mahdavi 21 Jan '10

21 Jan '10

{I beg your pardon if you receive multiple of this. I am not sure about its receive.} I hope I am in a right place. I heard that boost is this and that. I am new to boost but have 10 years of programming experience with c++. It is about 10 hours I am searching for a sample about how can I reach to a histogram. For clarity. Please (please I beg you) write some few line of code how to get a histogram. double s[] = { 0, .5 , .6 , .65 , .45 , .7 , .6 , .65 , .45 , .7 , .59 , .52 } ; I want histogram of s ?? I tried many boost codes but I failed all the time. Please help. -- View this message in context: http://old.nabble.com/Boost-is-complicated.-This-forum-too.-%28please-help-… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[GGL] Can't seem to use equals on multi_polygons
by Kef Schecter 21 Jan '10

21 Jan '10

When I try to use equals() on multi_polygons, the compiler blows up, giving a template error. I've tried this in CodeWarrior and MSVC. Using equals() on two polygon_2d's works fine, but it doesn't like it when I use multi_polygons. Is equals() for multi_polygons not implemented, or am I just missing something? I've attached a test program that demonstrates the problem. (I've defined my own integer-based types, like polygon_2di, because I need this to work on an embedded platform with no FPU. Using polygon_2d and doubles instead shows the same problem, though.) - Kef

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error LNK2005
by Kevin Li 21 Jan '10

21 Jan '10

Hello, when the run boost test cases (Version 1.41.0), I got quite a few LNK2005 errors. Below is an example when run a Data_Time test: msvcprt.lib(MSVCP80.dll) : error LNK2005: "public: __thiscall std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (??0?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@QAE@ABV01@@Z) already defined in dates_as_strings.obj msvcprt.lib(MSVCP80.dll) : error LNK2005: "public: __thiscall std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >::~basic_string<char,struct std::char_traits<char>,class std::allocator<char> >(void)" (??1?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@QAE@XZ) already defined in dates_as_strings.obj It seems to me that there is a conflict between system library and the Boost library, but I am not sure if this is a bug or the Boost library is not correctly built. Any clue would be very appreciated. Best regards, --Kevin _________________________________________________________________

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library for differentiation (interest research)
by DE 21 Jan '10

21 Jan '10

hi all recently i have interested in evaluating of derivatives of complicated functions and discovred that there is a finely developed technique which is called algorithmic differentiation (visit www.autodiff.org if you are interested) the resulting code using an imagined lib may look like this struct { template<typename type> type operator()(type x) //defining function { return sin(x); } } foo; //... double x = 42., f = foo(x), //evaluating function value df = deriv(foo, x); //evaluating derivative value notice that the function' code is untouched the very amazing thing is that the function may be arbitrarily complex it can even be a matrix inversion or eigenvalues evaluation so we get e.g. derivatives of eigenvalues with respect to system parameters gradients, jacobians and higher order derivatives are also possible there are numerous libraries implementing this technique and the questions are: - does it fit into boost collection of libraries? - is it worth building a distinct boost (well-designed) library or adopt a specific lib or to use other (non-boost) libs? and the like personally i am going to investigate the so called tangent mode (or direct mode which is very simple) and probably implement it if i don't find any suitable implementation for my own purposes -- Pavel

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shared_ptr/intrusive_ptr conflict
by Gennadiy Rozental 21 Jan '10

21 Jan '10

Hi, Following snippet fails to compile with gcc 4: ---------------- #include <boost/shared_ptr.hpp> #include <boost/intrusive_ptr.hpp> boost::shared_ptr<void> sharedPtr; template <class T> boost::shared_ptr<T> get_concrete() { return boost::static_pointer_cast<T,void>(sharedPtr); } int main() { boost::shared_ptr<int> p = get_concrete<int>(); } ---------------- due to the presence of intrusive_ptr.hpp. it seems like SFINAE should have kicked in. Any help with how to work this around? Do we need to fix above header? Gennadiy.

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[String Algo] error in ireplace_first or ireplace_all with std::wstring under gcc 3.4.2 (MingW)
by Doug Swanson 20 Jan '10

20 Jan '10

I apologize in advance if this is an inappropriate place to post this question. I posted it to the boost-users list half a week ago and got no replies, so I am trying here instead. The following code compiles and runs without error under g++ in Windows, GCC 3.4.2 (MingW): <code> #include <cstdio> #include <string> #include <boost/algorithm/string.hpp> using namespace std; using namespace boost; int main( void ) { string test = "This is a test"; ireplace_first( test, "test", "success" ); printf( "%s\r\n", test.c_str() ); return 0; } </code> The output is correct: "This is a success". If I change the above code to use a std::wstring instead, it will compile, but it will crash on execution: <code> #include <cstdio> #include <string> #include <boost/algorithm/string.hpp> using namespace std; using namespace boost; int main( void ) { wstring test = L"This is a test"; ireplace_first( test, L"test", L"success" ); printf( "%ws\r\n", test.c_str() ); return 0; } </code> Setting a breakpoint on std::terminate() in gdb gives the following backtrace: Breakpoint 1, 0x00407ae6 in std::terminate() () (gdb) bt #0 0x00407ae6 in std::terminate() () #1 0x00404dc2 in __cxa_throw () #2 0x004021d2 in std::__throw_bad_cast() () #3 0x00434c69 in std::ctype<wchar_t> const& std::use_facet<std::ctype<wchar_t> >(std::locale const&) (__loc=@0x22fe8c) at C:/Applications/Dev-Cpp//bin//../lib/gcc/mingw32//3.4.2//..//..//../../include/c++/3.4.2/bits/locale_facets.tcc:112 #4 0x0043415c in wchar_t std::toupper<wchar_t>(wchar_t, std::locale const&) ( __c=84, __loc=@0x22fe8c) at C:/Applications/Dev-Cpp//bin//../lib/gcc/mingw32//3.4.2//..//..//../../include/c++/3.4.2/bits/locale_facets.h:4553 #5 0x0041648c in bool boost::algorithm::is_iequal::operator()<wchar_t, wchar_t> (wchar_t const&, wchar_t const&) const (this=0x22fe8c, Arg1=@0x3e3df4, Arg2=@0x43702e) at C:/Applications/Boost_new/boost/algorithm/string/compare.hpp:71 #6 0x004163fb in boost::iterator_range<__gnu_cxx::__normal_iterator<wchar_t*, std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > > > boost::algorithm::detail::first_finderF<wchar_t const*, boost::algorithm::is_iequal>::operator()<__gnu_cxx::__normal_iterator<wchar_t*, std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > > >(__gnu_cxx::__normal_iterator<wchar_t*, std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > >, __gnu_cxx::__normal_iterator<wchar_t*, std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > >) const (this=0x22fe80, Begin={_M_current = 0x3e3df4}, End={_M_current = 0x3e3e10}) at C:/Applications/Boost_new/boost/algorithm/string/detail/finder.hpp:76 #7 0x00413fe8 in void boost::algorithm::find_format<std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, boost::algorithm::detail::first_finderF<wchar_t const*, boost::algorithm::is_iequal>, boost::algorithm::detail::const_formatF<boost::iterator_range<wchar_t const*> > >(std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >&, boost::algorithm::detail::first_finderF<wchar_t const*, boost::algorithm::is_iequal>, boost::algorithm::detail::const_formatF<boost::iterator_range<wchar_t const*> >) ( Input=@0x22ff50, Finder=@0x22fe80, Formatter={m_Format = {m_Begin = 0x43701e, m_End = 0x43702e, singular = false}}) at C:/Applications/Boost_new/boost/algorithm/string/find_format.hpp:146 #8 0x004141b5 in void boost::algorithm::ireplace_first<std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >, wchar_t[5], wchar_t[8]> (std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >&, wchar_t[5] const&, wchar_t[8] const&, std::locale const&) (Input=@0x22ff50, Search=@0x43702e, Format=@0x43701e, Loc=@0x22ff40) at C:/Applications/Boost_new/boost/algorithm/string/replace.hpp:259 #9 0x004014e8 in main () at test.cpp:11 I am not competent enough with Boost to understand what the call stack is telling me, except that __throw_bad_cast( ) is the source of the crash. ireplace_all gives the same behavior as ireplace_first above. Furthermore, the problem does not arise if I use replace_first or replace_all instead of ireplace_first or ireplace_all. It compiles and runs correctly. Finally, the problem does not arise if I compile using MSVC 2008. It compiles and runs correctly. Does this indicate a problem with gcc (MingW) unicode support? Is there an easy way to circumvent it? Thank you very much for any suggestions!

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[gil] native image format loaders/savers
by Domagoj Saric 20 Jan '10

20 Jan '10

Would a contribution to GIL in the form of alternate 'native' (e.g. using GDI+ on Windows) implementations (to remove the libjpeg, libtiff, libpng and zlib requirements) of image format parsers be accepted? -- "That men do not learn very much from the lessons of history is the most important of all the lessons of history." Aldous Huxley

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[Boost.tracer] library request
by Andrew Chinkoff 20 Jan '10

20 Jan '10

[Boost.tracer] library request is founded on a desire to trace some statistics about program execution. The sample program below demonstrates these statistics. Sample program file: ******** START OF FILE ******** #include <tracer.h> void foo() { TRACE_LIFETIME; usleep(rand() % 100000); } int main() { TRACE_LIFETIME; for(int i = 0; i < 100; ++i) foo(); } ******** END OF FILE ******** Produced log file: ******** START OF FILE ******** All the program time: 05265686 us (micro secs) TRACE POINT: Function: int main() Calls: 0000000001 times Average T between calls: 0000000000 us Average life T: 0005264459 us File: main.cpp Line: 00000009 TRACE POINT: Function: void foo() Calls: 0000000100 times Average T between calls: 0000051665 us Average life T: 0000052606 us File: main.cpp Line: 00000004 ******** END OF FILE ******** Comment: TRACE_LIFETIME is a MACRO that traces some scope statistics, namely: "Function" - the function name where the scope is; "Calls" - number of entries into this scope; "Average T between calls" - average time period between "Calls"; "Average life T" - average time spent in this scope. Conclusion: I think it is reasonable to introduce this trace functionality into (for example) boost::tracer namespace. I had wrote tracer.h and tracer.cpp source files and I wish Boost community to consider them. Thank You.

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[1.42.0] Beta 1 release candidate
by Beman Dawes 20 Jan '10

20 Jan '10

Release candidates for 1.42.0 beta 1 are available at http://boost.cowic.de/rc/ Please download, do a build, and report results here. Also let us know if you spot any problems or have any other comments. Thanks, --Beman

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