February 2004 - Boost-users

boost::bind throws exception with VisualStudio 7.1
by Cheenu Srinivasan 03 Feb '04

03 Feb '04

The following program throws a bad_function_call exception when compiled with VisualStudio 7.1. It happens with both boost-1.30.2 and boost_1_31_0_rc2. No problems when compiled with g++ 2.95.1 on solaris. ---- #include <boost/bind.hpp> #include <boost/function.hpp> using namespace boost; #include <iostream> using namespace std; double f(int i, double d) { cout << "int = " << i << endl; return d; } main() { boost::function<double (int)> bound_func = boost::bind(f, _1, 1.234); int i = 99; cout << bound_func(i) << endl; } ---- Peter Dimov wrote: >Could you please post a message to the developer's list >(or if that's a problem, post it here) with an appropriately alarming >subject :-) containing a complete program that demonstrates the problem? >(So >that we try to fix it before 1.31 goes out.) _________________________________________________________________ Get a FREE online virus check for your PC here, from McAfee. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963

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RE: [Boost-users] newbie question about boost::regex and memory leaks
by Gregory, Matthew 03 Feb '04

03 Feb '04

Ben Hastings wrote: > The only memory allocation I can see is for the array that pclasses > points to and the strings in it. These are freed in do_free() which is > called by the destructor of the last instance of w32_traits_base. > Since each of the derived classes of w32_traits_base > (w32_regex_traits<char> and w32_regex_traits<wchar_t>) has a static > instance of itself as a member, the memory will not be freed until after > main() returns. So if you call _CrtDumpMemoryLeaks() at the end of > main() this memory will wrongly be reported as leaked. Ben, this was exactly my problem. Sorry for the bonehead and thanks for the help. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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RE: [Boost-users] newbie question about boost::regex and memory leaks
by Ben Hutchings 03 Feb '04

03 Feb '04

Gregory, Matthew <matt.gregory(a)oregonstate.edu> wrote: > Forgive the likely simple question ... > > I am using boost-1.30.2 regex library in a C++ console app and have > been using VC7 to debug memory leaks through the _CrtDumpMemoryLeaks() > function. Where is this called from? > It reports numerous memory leaks on the first time I use a > boost::regex object, albeit relatively small leaks. For example, if I > use > > boost::regex statsRe("^\\s+8\\s+ENVI\\s+AX4.*") > > there are a number of memory leaks from memory allocated in the > boost::re_detail::w32_traits_base::do_init() block. > > I am wondering if I am doing something wrong in that no destructor > gets called for these objects or if small memory leaks are to be > expected when using these objects. The only memory allocation I can see is for the array that pclasses points to and the strings in it. These are freed in do_free() which is called by the destructor of the last instance of w32_traits_base. Since each of the derived classes of w32_traits_base (w32_regex_traits<char> and w32_regex_traits<wchar_t>) has a static instance of itself as a member, the memory will not be freed until after main() returns. So if you call _CrtDumpMemoryLeaks() at the end of main() this memory will wrongly be reported as leaked.

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[Date-Time] Issues
by Andrew V. Bronnikov 03 Feb '04

03 Feb '04

Hello, All! When I was familiarized with the great Boost Library one of the most inspiring part of it was the Date-Time Library. Date and time issues are very important in our project related with time series, so I immediately started to read docs, and tried to incorporate the lib as it became possible for us. As usual, problems hadn't kept waiting... :) Issues: 1. why gregorian::date and posix_time::ptime have no default constructors (possibly initializing them into some special value - good candidates are not_a_date_time, neg_inf or local_time (see next issue))? Lack of default ctors doesn't allow direct use of date-time objects in tuples and other containers requiring default-constructible classes. 2. why special_values enum has no "local_time" (or "now") item? It seems "special" enough, and - more important - it allows to pass the "initialize as current time" directive as a time initialization policy in templates. 3. why date, ptime, durations have no setters for their components (days, hours, minutes etc)? I guess it related with validity checking issues - am I right, or there are some other reasons? 4. why hours(), minutes() etc are classes, not simple time_duration factory functions? What the another level of inheritance for? Consider using a time_duration in lambda expressions (e.g. in the Spirit semantic actions): posix_time::time_duration dt; .... rule<> hours = uint_p [var(dt) += posix_time::hours(_1)] This will not compile because hours() is not a function. Instead, I must use something like a lazy constructor: rule<> hours = uint_p [var(dt) += bind(constructor<posix_time::hours>(), _1)] but it looks not so short as before. And - surprise! - it doesn't compile too, just because of the next problem: 5. neither of date, ptime or time_duration defines operator+=(). What is the reason for denying it? It seems quite natural to have a set of assignment operators for date_time classes, isn't it? 6. it would be great if GDTL classes will support explicit/implicit conversion functions/operators from/to older standard types like a time_t etc. It will allow smoother transition from old libraries to the GDTL. Thanx for the great work anyway! With best regards, Andrew V. Bronnikov.

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newbie question about boost::regex and memory leaks
by Gregory, Matthew 02 Feb '04

02 Feb '04

Forgive the likely simple question ... I am using boost-1.30.2 regex library in a C++ console app and have been using VC7 to debug memory leaks through the _CrtDumpMemoryLeaks() function. It reports numerous memory leaks on the first time I use a boost::regex object, albeit relatively small leaks. For example, if I use boost::regex statsRe("^\\s+8\\s+ENVI\\s+AX4.*") there are a number of memory leaks from memory allocated in the boost::re_detail::w32_traits_base::do_init() block. I am wondering if I am doing something wrong in that no destructor gets called for these objects or if small memory leaks are to be expected when using these objects. Thanks, matt

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RE: Boost-users Digest, Vol 118, Issue 2
by Cheenu Srinivasan 02 Feb '04

02 Feb '04

Peter Dimov wrote: >Cheenu Srinivasan wrote: > > > > With MSVC 7.1. the exception is thrown with both 'bound_func = > > bind(...)' and 'bound_func(bind(...))'. But I tried it with > > g++/solaris and it works. So it does look like a bug with the MS > > compiler. Thanks. > >It works for me in MSVC 7.1, but I'm using the CVS version of Boost. It may >be a bug in 1.30.2 (if that's what you are using). You may download 1.31 >release candidate 2 from > > http://www.esva.net/~beman/boost_1_31_0_rc2.zip > >to verify that the problem does not occur with the immininent 1.31 release. I tried VisualStudio 7.1 with boost_1_31_0_rc2 with the same results: a bad_function_call exception. I tried it on two different PCs (same version of VisualStudio, of course). _________________________________________________________________ Check out the new MSN 9 Dial-up fast & reliable Internet access with prime features! http://join.msn.com/?pgmarket=en-us&page=dialup/home&ST=1

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Re: [Boost-users] return type of boost::bind
by Cheenu Srinivasan 02 Feb '04

02 Feb '04

[Reposting under corect subject.] Peter Dimov wrote: >Cheenu Srinivasan wrote: > > > > With MSVC 7.1. the exception is thrown with both 'bound_func = > > bind(...)' and 'bound_func(bind(...))'. But I tried it with > > g++/solaris and it works. So it does look like a bug with the MS > > compiler. Thanks. > >It works for me in MSVC 7.1, but I'm using the CVS version of Boost. It may >be a bug in 1.30.2 (if that's what you are using). You may download 1.31 >release candidate 2 from > > http://www.esva.net/~beman/boost_1_31_0_rc2.zip > >to verify that the problem does not occur with the immininent 1.31 release. I tried VisualStudio 7.1 with boost_1_31_0_rc2 with the same results: a bad_function_call exception. I tried it on two different PCs (same version of VisualStudio, of course). _________________________________________________________________ Let the new MSN Premium Internet Software make the most of your high-speed experience. http://join.msn.com/?pgmarket=en-us&page=byoa/prem&ST=1

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cannot compile boost with dev-cpp 4.9.8.0
by Vikrant Rathore 02 Feb '04

02 Feb '04

HI, Anyone has compiled boost library successfully using dev-cpp the new version. I try compiling it and it gives many errors. I follow the following qway to compile: C:\projects\boost> C:\projects\boost>set path=c:\dev-cpp\bin C:\projects\boost>set MINGW_ROOT_DIRECTORY=c:\dev-cpp C:\projects\boost>set MINGW_BIN_DIRECTORY=c:\dev-cpp\bin C:\projects\boost>set MINGW_INCLUDE_DIRECTORY=c:\dev-cpp\include C:\projects\boost>set MINGW_STDLIB_DIRECTORY=c:\dev-cpp\lib C:\projects\boost>bjam -sTOOLS=mingw I tried many different option including usig MSYS with no luck. Thanks with best regards, Vikrant

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Compliation speed of Boost.Signal in C++ Builder 5
by Ben Chan 02 Feb '04

02 Feb '04

Dear All, I'm new to boost and trying to use boost.signal in my BCB 5.0 project,everything works fine except my project compilation speed was horribly slow down.Once I included the <signal.hpp>,the compiler have to compile extra thousands line of code even my project is empty.I did put the signal.hpp file in my pre-compiled header and include the static lib, but seems it can't help much. Any suggestion to improve the compliation speed in BCB?VC7.0 seems compile pretty fast. Thx Ben _________________________________________________________________ Linguaphone : Learning English? Get Japanese lessons for FREE http://go.msnserver.com/HK/30476.asp

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Re: [Boost-users] return type of boost::bind
by Cheenu Srinivasan 01 Feb '04

01 Feb '04

Peter Dimov wrote: > Cheenu Srinivasan wrote: > > Duane Murphy wrote: > >> The return type of boost::bind is fairly indeterminate. In order to > >> call a bound function at a later time, look at boost::function. It > >> does a nice job of holding on to a function that uses boost::bind. > > > > I looked at "Using bind with Boost.Function" in the boost::function > > docs. Mimicing that, for my example, I tried: > > > > boost::function<double (int)> bound_func = boost::bind(f, _1, 1.234); > > int i = 99; > > cout << bound_func(i) << endl; > > > > but it throws a bad_function_call exception when bound_func(i) is > > invoked. How do I use boost::function for this situation? > > Works for me; it's probably a compiler bug. Which compiler are you using? > > Try > > boost::function<double (int)> bound_func( boost::bind(f, _1, 1.234) ); > > instead. With MSVC 7.1. the exception is thrown with both 'bound_func = bind(...)' and 'bound_func(bind(...))'. But I tried it with g++/solaris and it works. So it does look like a bug with the MS compiler. Thanks.

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