April 2013 - Boost - lists.preview.boost.org

required toolsets
by Steven Watanabe 15 May '14

15 May '14

AMDG The list of required toolsets in explicit-failures-markup.xml is out-dated. Therefore, if no one objects, I propose setting it to the following: msvc-10.0, msvc-11.0, gcc-4.6, gcc-4.7, clang-darwin-11, clang-darwin-4.2.1, clang-linux-3.1, clang-linux-3.2, gcc-mingw-4.7, gcc-mingw-4.6 (two releases of each major compiler that appears in both the trunk and release regression tests) The sole effect of this is to determine which toolsets appear in the issues list: http://www.boost.org/development/tests/trunk/developer/issues.html In Christ, Steven Watanabe

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[Macro]Test Case grouping using Traits
by Hemanth Choudary M V (RBEI/ETA1) 13 Jan '14

13 Jan '14

Hello, I have observed that in native unit test framework(c++), there is an option to group test cases using attributes which are reflected as traits in the Test Explorer window in MS VS2012. Following is a an example of the same: BEGIN_TEST_METHOD_ATTRIBUTE(TestMethod3) TEST_OWNER(L"SuperMan") TEST_PRIORITY(2) TEST_METHOD_ATTRIBUTE(L"Category",L"Slow") END_TEST_METHOD_ATTRIBUTE() TEST_METHOD(TestMethod3) { Assert::AreEqual(2,6); } How can this be achieved via Boost Unit Test Library? Are there macros to achieve the same? Mit freundlichen Grüßen / Best Regards, Hemanth Choudary MV RBEI/ETA1

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safe bool not safe enough ?
by John Maddock 28 Jul '13

28 Jul '13

Just discovered (oops!) that the so called safe bool ideom is not as safe as it appears, for example: class Testable { bool ok_; typedef void (Testable::*bool_type)() const; void this_type_does_not_support_comparisons() const {} public: explicit Testable(bool b=true):ok_(b) {} operator bool_type() const { return ok_==true ? &Testable::this_type_does_not_support_comparisons : 0; } }; Testable t(true); bool b = t; // Compiles OK - Ooops! Which is causing multiprecision to misbehave when used in conjunction with uBlas: https://svn.boost.org/trac/boost/ticket/8292#comment:2 I guess making the conversion explicit in C++11 mode would help (I still need to test that), but is there a C++03 solution? Thanks, John.

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[GIL] Can image::recreate reuse the memory?
by TONGARI 06 Jun '13

06 Jun '13

Hi, I'd expect image::recreate to reuse the memory much like std::vector::resize, but looked into the code shows that it creates a new one and swaps... So, is there a way to 'resize' the image without reallocating if the internal memory is sufficient? Thanks

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[thread] countdown_latch
by Michael Marcin 27 May '13

27 May '13

I recently ran across the need to spawn a thread and wait for it to finish its setup before continuing. The accepted answer seems to be using a mutex and condition variable to achieve this. However that work clutters up the code quite a bit with the implementation details. I came across Java's CountDownLatch which does basically the same work but bundles it up into a tidy package. It seems to be a fairly trivial but useful abstraction. implementation: http://codepad.org/E8kd2Eb8 usage: class widget { public: widget() : latch( 1 ) , thread_( [&]{ thread_func(); } ) { latch.wait(); } private: void setup(); void run(); void thread_func() { setup(); latch.count_down(); run(); } countdown_latch latch; std::thread thread_; };

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[Fusion] another nil issue
by Rich E 23 May '13

23 May '13

I see there was work about 5 months ago to avoid the Obj-C++ nameclash with nil in Boost.Fusion: https://github.com/boostorg/fusion/commit/12d2898287a124ff4b398fd3fff512b6f… Thanks for that as there are alot of use using boost in this scenario. However, I have found another couple nameclashes that prevented me from linking against Boost.Log in the latest trunk on OS X with clang, when trying this sample code: http://boost-sandbox.sourceforge.net/libs/log/example/doc/tutorial_trivial_… Attached is the changeset I needed to make to build. Does this seem acceptable to the maintainers? Best, Rich

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[gil] Ok to merge new gil's extension to release branch?
by Christian Henning 19 May '13

19 May '13

Hi, is it ok? The merge would include io, toolbox, numerics and some other changes to gil's code itself. Regards, Christian

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[GSOC] XML library of Boost
by Amos Ji 12 May '13

12 May '13

Hi All, I'm a graduate student from Fudan University in China. And I hope to contribute some code to Boost during the GSOC. I've scanned the idea page. The ideas in the page are all very interesting and challenging. But what I'm interested in most is XML library, which is at the bottom of page. I think the XML format is the most popular standard for storing information so it's important for Boost to have a good XML library. However, I know Boost contains RapidXML in property_tree library to parse XML file. So what I want to make sure is I need to implement a new XML parser in this project instead of make enhancement for RapidXML. Am I correct? If so, I have some ideas to share with you. In my opinion, an XML parser must be able to do these things: 1. To Iterate over DOM nodes tree; 2. To access the values of nodes and their attributes quickly; 3. To insert or delete nodes or attribute of an exact node easily; 4. To generate new XML from the structure which stores XML in the library. And there are some optional function too: 1. To support XPATH; 2. To validate whether the XML file is valid; 3. To support various encoding; 4. To manage memory better; 5. To support regular expression. The ideas are not mature now. I'll improve them in my proposal. In fact, it's not easy to implement a perfect XML parser but I'll do my best. And I have another question. Who will mentor this XML library project? Thanks for your patience to read this email. Sincerely, Mingchao -- Amos Ji(Mingchao Ji) Master in School of Information Science and Engineering, Fudan University MSN: jmc891205(a)hotmail.com E-mail: jmc891205(a)gmail.com

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[bootstrap/1.53] jam0.exe crashes when bootstrapping for VC2012 AMD64
by rjeczalik 11 May '13

11 May '13

Hi, I'm trying to build Boost 1.53 using VC2012 amd64 (toolset=msvc-11.0 address-model=64) and Windows Server 2012 Standard. Bootstrapping fails with jam0.exe crash - some crash info: Crash stacktrace: ntdll.dll!000007f9bc781069() KernelBase.dll!000007f9b978764e() KernelBase.dll!000007f9b97d3658() jam0.exe!_findnext64i32(__int64 hFile, _finddata64i32_t * pfd) Line 165 jam0.exe!file_dirscan(_object * dir, void (void *, _object *, int, __int64) * func, void * closure) Line 180 jam0.exe!builtin_glob(frame * frame, int flags) Line 718 jam0.exe!function_run(_function * function_, frame * frame, _stack * s) Line 3390 jam0.exe!evaluate_rule(_object * rulename, frame * frame) Line 264 jam0.exe!function_call_rule(_jam_function * function, frame * frame, _stack * s, int n_args, const char * unexpanded, _object * file, int line) Line 468 jam0.exe!function_run(_function * function_, frame * frame, _stack * s) Line 3950 jam0.exe!parse_file(_object * f, frame * frame) Line 57 jam0.exe!main(int argc, char * * argv, char * * arg_environ) Line 488 jam0.exe!__tmainCRTStartup() Line 241 jam0.exe!mainCRTStartup() Line 164 kernel32.dll!000007f9b9de167e() ntdll.dll!000007f9bc7a3501() Line where it crashed was: if (!FindNextFile((HANDLE)hFile, &wfd)) { I've tried to watch the values of arguments passes to FindNextFile() - hFile looked like proper handle, however wfd.cFileName and wfd.cAlternateFileName contained garbage. Is this a known issue for 1.53? I've compiled version 1.52 using the same environment and the same configuration and everything went ok, I did not manage to reproduce the crash. It looks like only version 1.53 is affected. Regards, Rafael Jeczalik

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Re: [boost] [log] Patch: rotating file collector
by Andrey Semashev 10 May '13

10 May '13

On Tue, Apr 23, 2013 at 3:58 PM, Alexander Arhipenko <arhipjan(a)gmail.com>wrote: > > I've added implementation of rotating file collector - > the patch against boost log trunk attached. > This is not the final version, I'm going at least to finish most of the > TODOs. > > However, it would be nice to receive feedback and questions from > library author as well as from people interested in this feature. > > Andrey, could you please find several minutes to review the attached patch? > Thanks for the patch. I didn't look deeply into it yet but from the first glance it looks like you changed the existing file collector rather than introduce an alternative one. Am I right? If so, could this be made as a pure addition rather than modification? I would prefer to keep the current behavior also available for the users. Also, I would like to discuss following question with you : > rotate_file invocation in ~text_file_backend - > I would prefer to have this call during text_file_backend construction > phase. > I'll have to take a closer look later to answer that but it seems odd to have to rotate something when nothing have been written yet. The rotate_file call is intended to place the written file to the storage governed by the collector, and at construction this file hasn't been created yet. Could you describe why you need this?

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