November 2011 - Boost-users

Re: [Boost-users] [locale] Quick questions
by Jookia 08 Nov '11

08 Nov '11

I made some kind of limited test case: http://www.mediafire.com/?g5axcnch8q20ixo

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[variant] a question about recursive typedef
by gongyiling 08 Nov '11

08 Nov '11

Hello, everyone: I want write a general linked list(any element in the list may be a node or nested general linked list, so recursive). I think general linked list could by defined as following(see spirit's tutorial mini_xml): glist = *glist_node glist_node = node | glist so here is the typedef according to the above rules: struct node { int data; }; typedef boost::variant<node, boost::recursive_wrapper<glist> > glist_node; //typedef 1 typedef std::list<glist_node> glist; //typedef 2 so the problem comes here, in the typedef 1, how can I forward declare glist? I know this is not a problem if I define glist as a struct or class, but I think the all-powerful library must has a beautiful solution, if any one has a solution, please let me know.

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regex memory leaks
by jamich - Post 08 Nov '11

08 Nov '11

I have problem with memory leaks. I use boost version 1.47. I compiled boost libray by Visual Studio 2010 SP1. My testing code is here: #include "stdafx.h" #include <stdio.h> #include <boost/regex.hpp> void Memtest() { boost::regex e("^(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})(:\\d{1,5})?$"); if ( boost::regex_match("1.a.1.1", e) ) std::cout << "ok" << std::endl; if ( boost::regex_match("1.1.1.1", e) ) std::cout << "ok" << std::endl; } int main(int argc, _TCHAR* argv[]) { _CrtSetReportMode( _CRT_ERROR, _CRTDBG_MODE_DEBUG ); _CrtMemState state; _CrtMemCheckpoint(&state); Memtest(); _CrtMemState newState, diff; _CrtMemCheckpoint(&newState); if(_CrtMemDifference(&diff, &state, &newState)) { _CrtMemDumpStatistics(&diff); } return 0; } This code comes from simple console based project. Debugger gives me these output: 0 bytes in 0 Free Blocks. 5544 bytes in 16 Normal Blocks. 0 bytes in 0 CRT Blocks. 0 bytes in 0 Ignore Blocks. 0 bytes in 0 Client Blocks. Largest number used: 9333 bytes. Total allocations: 13620 bytes. Could anyone help me to resolve these memory leaks? Thanks, Michal

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Re: [Boost-users] [locale] Quick questions.
by Jookia 08 Nov '11

08 Nov '11

>> Use std::locale::global(locale_you_need_to_install) That's what I've originally been doing (You can see the code at http://sprunge.us/ULEV ), but it doesn't work. Also, I'm new to mailing lists. How do I specifically reply to a post properly? Currently I'm just typing "Re: [Boost-users] [locale] Quick questions." in the subject bar.

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[locale] Quick questions
by Jookia 07 Nov '11

07 Nov '11

Hey! I have some small questions about Boost.Locale. 1. Is it safe to assume that Boost.Locale API methods (like gettext) return UTF-8 strings, or are they locale dependent? 2. I use a custom domain, but when calling gettext("...") I still get lovely English text. However, calling gettext("...", std::locale()) fixes that. Is there some way to set the default domain/locale for gettext so I can simply write gettext("...")? 3. What's the deal with the whole locale/$LANG/LC_MESSAGES/$domain.mo folder structure? I know it has Unix heritage, but why is it explicity forced? It seems like a complex structure compared to locale/$LANG-$domain.mo.

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multi-array and pdes
by petros 07 Nov '11

07 Nov '11

Hi, These can very well be very naive questions, since I am relatively new to this - apologies..: I am trying to write a pde solver for a 3D problem. Multi-array seems like a very natural choice for a data structure to store the functtion values. The method I am trying to use is operrator splitting. This amounts to solving a tridiagonal system for each dimension in sequence. Suppose then that I have a MA( M, N, L ): It is highly desirable to maintain this xyz (let's call it) "logical" system of reference since incorporation of boundary conditions and stencil calculations would be conceptually straightforward -otherwise very complicated. The idea being that, I would then have the tridiagonal opertator ( and rhs) in the "rotated" system and all other calculations in the "logical" one. Therefore, I need some fascility to rotate my MA, from the xyz to yzx etc (cyclically). Is there functionality ( as a view to the data ) that would allow me to do this off-the-shelve? Also, a couple of other points: -If I wanted to use views to subgrids, in parallelized calculations, are there memory allocations that happen under the hood for which I should worry (for performance)? -Is a one dimensional MA usable? -Are there adapters between 2D MAs and uBlas matrices? Thank you very much for your help in advance! P-

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[atomic] review results
by Tim Blechmann 07 Nov '11

07 Nov '11

hi all, unfortunately only few reviews of boost.atomic arrived in time, however i count 3 YES and no NO, so i am happy to say: Helge Bahmann's boost.atomic library is ACCEPTED. since the library is an implementation of a c++11 feature for c++03, design, API and semantics are mostly fixed. many comments are going into details of the implementation, so i won't sum them all up ... iac, helge already said he wants to address the raised issues, the main points are summarized below. full implementation of the c++11 interface: the library currently only implements a subset of the c++11 library. it lacks the functional interface for integral atomic types and the ATOMIC_VAR_INIT / ATOMIC_FLAG_INIT macro. quickly consulting the latest draft that i currently have at hand the following two functions are missing as well: template <class T> T kill_dependency(T y); void atomic_signal_fence(memory_order); i encourage helge to provide a full implementation of the interface. documentation: the documentation is currently lacking a good API reference. i would therefore encourage helge to provide a doxygen-generated reference section. there were some concerns that it assumes that readers will have to be familiar with concurrency. maybe it is a good idea to point to some literature/tutorials about concurrent programming and/or to c++11 atomics. the section of real-world examples could probably include a link to shavit/herlihy's book `the art of multiprocessor programming'. it would also be helpful to have a detailed specification, if a platform/compiler combination supports a specific type natively (with run-time dispatching or specific compiler flags) ... maybe in form of a table. shared memory support/multi-module support: in multi-module applications and when using shared memory, the blocking emulation of atomics can cause troubles. for multi-module applications this can be resolved by placing the spinlock pool inside a shared library. shared- memory support could be realized by associating a (spin)lock with each blocking atomic<> instead of using a pool of spinlocks. boost should definitely provide atomics which support shared memory, either by default or by an additional implementation which is placed in the boost::interprocess namespace. i would like to thank helge for implementing boost.atomic and submitting it to boost and everyone who participated in the review. cheers, tim review manager

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[Boost.PropertyTree] Is it possible to populate a tree with user defined parser?
by Gábor Márton 07 Nov '11

07 Nov '11

Hi, I would like to use PropertyTree as a higher level interface to access our project's config data. However, the config data can be accessed only through C API calls, so I cannot use the XML or INI parser. I suppose that PropertyTree has a polimorfic implementataion, which provides an interface for which a parser must conform, am I right? Thanks, Gabor

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bcp doesn't work as expected
by Max Limper 06 Nov '11

06 Nov '11

Hi everyone, I'm trying to use boosts shared_ptr class, and only that one - I was happy to see that boosts provides such a cool tool as bcp. However, it seems that the installation that bcp performs is not complete in my case. When compiling my project, I first found out that "boost/config/user.hpp" was missing. So I copied that one manually and assumed that it was just a little bug since that one does just includes comments and might therefore have been ignored by bcp for some reason. But now, I still find that "boost/config/compiler/visualc.hpp" is missing and my project is unable to compile. According to the bcp description ( http://www.boost.org/doc/libs/1_37_0/tools/bcp/bcp.html) I was assuming that bcp should install all compiler configs that might be necessary for any random platform. Here's how I used bcp after I built it (Windows7, VC10): "{path-to-the-bcp-build-dir}/bsp.exe shared_ptr.hpp E:\SDK\boost_1_47_0_dependencies" , invoked from the root of the freshly downloaded boost directory E:\SDK\boost_1_47_0. Did I make a mistake, or is this a bug? Thanks a lot in advance! Regards, Max

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[variant] is the which() function part of variant's public API?
by Nathan Ridge 06 Nov '11

06 Nov '11

which() is a public member function of variant, but I don't see any mention of it in the documentation. Can I assume this is part of the public API (i.e. it won't go away, won't change its behaviour in future releases) or not? (For example, I am writing a function to serialize a variant and thinking that one implementation might be to write the which() followed by the object). Thanks, Nate

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