March 2012 - Boost - lists.preview.boost.org

bad include guards
by Steven Watanabe 26 Jan '17

26 Jan '17

AMDG The following pairs of files have identical include guards ./boost/concept_check/general.hpp ./boost/concept/detail/msvc.hpp ./boost/concept_check/msvc.hpp ./boost/concept/detail/msvc.hpp ./boost/filesystem/cerrno.hpp ./boost/cerrno.hpp ./boost/interprocess/containers/tree.hpp ./boost/interprocess/containers/detail/tree.hpp ./boost/mpl/min_max.hpp ./boost/mpl/max.hpp ./boost/mpl/vector/aux_/front.hpp ./boost/mpl/list/aux_/front.hpp ./boost/multi_index/identity_fwd.hpp ./boost/multi_index/identity.hpp ./boost/python/pointee.hpp ./boost/python/detail/pointee.hpp ./boost/spirit/phoenix/closures.hpp ./boost/lambda/closures.hpp ./boost/xpressive/proto/v1_/proto_typeof.hpp ./boost/xpressive/proto/proto_typeof.hpp ./libs/config/test/boost_no_dep_nested_class.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_mem_templates.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/config/test/boost_no_std_allocator.ipp ./libs/config/test/boost_has_vc6_mem_templ.ipp ./libs/conversion/test.hpp ./libs/any/test.hpp ./libs/interprocess/example/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/expand_bwd_test_template.hpp ./libs/interprocess/test/allocation_test_template.hpp ./libs/interprocess/test/printcontainer.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/interprocess/test/print_container.hpp ./libs/interprocess/example/printcontainer.hpp ./libs/iostreams/test/detail/utf8_codecvt_facet.hpp ./boost/detail/utf8_codecvt_facet.hpp ./libs/regex/test/regress/test_regex_search.hpp ./libs/regex/test/regress/test_partial_match.hpp ./libs/serialization/test/C.hpp ./libs/serialization/test/A.hpp ./libs/xpressive/perf/regex_comparison.hpp ./libs/regex/performance/regex_comparison.hpp ./tools/inspect/time_string.hpp ./tools/common/time_string.hpp In Christ, Steven Watanabe

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Arguing about names in Boost libraries
by Edward Diener 06 May '15

06 May '15

What is wrong with the people commenting on libraries for Boost who are so concerned about the names being used ? We are talking only about C++ identifiers and yet there are now endless discussions where people disagree on names or argue that some name is not what they want or that they like some other name, with a list of names that they find adequate. This is irrelevant. There is something mentally wrong about all those peoples spending endless amounts of time around this issue. I notice this does not happen nowadays for just one library but for ever single library, or proposed library, which is mentioned on this mailing list. Is this the way all of you people actually work in your daily jobs, or on your own projects, spending hours and days arguing with others about C++ identifiers for every little thing ? Are you not aware of the absurdity of your endless remarks ? Grow up ! Surely there are better things to do than carry on endlessly about some name, that is should be x or y or z or some other inane preferable list. It's time for somebody to say this, so I will do it. A C++ identifier name, as long as it is vaguely about what the functionality entails, is perfectly adequate. It does not have to satisfy everyone in the universe. Period !

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Why no non-null smart pointers?
by Ross MacGregor 29 Apr '14

29 Apr '14

I just created a very small smart pointer libary for our project. It will contain two types of shared pointers: SharedHandle and NullableSharedHandle. SharedHandle will be a shared pointer that cannot be null by ensuring a non-null construction while NullableSharedHandle will basically be a typedef for boost::shared_ptr. I firmly believe that code can be made more reliable by minimizing the use of nullable pointers. To this end, I think it is important that we start using non-null pointer types. Ideally the compiler would be able to understand a non-null pointer and catch bugs at compile time, but I think we can still improve things with a few runtime checks. If we make sure that a shared pointer is constructed with a non-null pointer and ban any reset() type methods, we guarentee that it points to something. This can be beneficial for the following reasons: 1. Any function that uses this type will no longer be burdened with precondition checks to make sure variables of this type are not null. 2. It's type is simply more explicit and better explains its function. 3. Moving the non-null check to the creation phase will reduce the possibility of encountering null pointer exceptions at runtime (assuming there are many more pointer references than constructor calls). So my little pointer library seems to make a lot of sense, but if so why hasn't this simple smart pointer variation made it into boost yet? Has this been discussed somewhere already? My search on non-null smart pointers is not revealing much discussion on the topic. Regards, Ross

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[mpl] integral_c [type_traits] integral_constant limits
by vicente.botet 21 Oct '13

21 Oct '13

Hi, I was testing Boost.Ratio with gcc-4.6 c++0x and I get some compile errors when instantiating std::cout << boost::mpl::integral_c< boost::intmax_t, boost::integer_traits<boost::intmax_t>::const_max >::value ; ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp: In instantiation of 'mpl_::integral_c<long long int, 0x7fffffffffffffffll>': ratio_io\ratio_io.pass.cpp:24:6: instantiated from here ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp:72:96: warning: integer overflow in expression [-Woverflow] ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp:72:96: error: '-0x8000000000000000ll' is not a valid template argument for type 'long long int' because it is a non-constant expression ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp:72:96: error: '-0x8000000000000000ll' is not a constant expression integral_wrapper.hpp:72 contains typedef AUX_WRAPPER_INST( BOOST_MPL_AUX_STATIC_CAST(AUX_WRAPPER_VALUE_TYPE, (value + 1)) ) next; The same line pass with gcc-4.6, gcc-4.5 and gcc-4.5 c++0x with just a warning. ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp: In instantiation of 'mpl_::integral_c<long long int, 0x7fffffffffffffffll>': ratio_io\ratio_io.pass.cpp:23:6: instantiated from here ..\..\..\../boost/mpl/aux_/integral_wrapper.hpp:72:96: warning: integer overflow in expression [-Woverflow] integral_c is by integral_constant, but integral_constant doesn't needs next a prior types. This means that with the current implementation we can not use integral_constant with the max value of the type. Do you think this is a bug in integral_constant? Best, _____________________ Vicente Juan Botet Escribá http://viboes.blogspot.com/

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[asio] Randomly having problems reading from the socket
by Torben Wiggerich 29 Jul '13

29 Jul '13

Hi all, I have some problems using the boost.asio.read for a TCP-socket. So far it works fine, but it randomly stops the transfer for at least 5 seconds. To resolve the error I used a simple synchronous server and client from the boost examples and modified it too send a larger amount of data. (307400 Bytes; this size comes from the program I'm trying to get run). On the client side I also changed the reading from the socket to read the complete data with boost.asio.read and transfer_all as argument. Both, server and client, measure the time for sending and reading to the socket and will give an error if it needs more than 1 second. Here is the sourcecode for the server: #include <iostream> #include <string> #include <boost/asio.hpp> #include <boost/date_time/posix_time/posix_time.hpp> using boost::asio::ip::tcp; using namespace boost::posix_time; int main() { try { boost::asio::io_service io_service; tcp::acceptor acceptor(io_service, tcp::endpoint(tcp::v4(), 8002)); tcp::socket socket(io_service); acceptor.accept(socket); unsigned char * array = new unsigned char[307400]; for (;;) { boost::system::error_code ignored_error; ptime startTime = microsec_clock::universal_time(); boost::asio::write(socket, boost::asio::buffer( array, 307400 ), boost::asio::transfer_all(), ignored_error); time_duration neededTime = microsec_clock::universal_time() - startTime; if ( neededTime.total_milliseconds() > 1000 ) { std::cout << "ERROR needed too much time: " << neededTime.total_milliseconds() << "ms" << std::endl; } } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } My client sourcecode: #include <iostream> #include <boost/array.hpp> #include <boost/asio.hpp> #include <boost/date_time/posix_time/posix_time.hpp> using boost::asio::ip::tcp; using namespace boost::posix_time; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: client <host>" << std::endl; return 1; } boost::asio::io_service io_service; boost::asio::ip::tcp::endpoint endpoint( boost::asio::ip::address::from_string( argv[1] ), 8002 ); tcp::socket socket(io_service); boost::system::error_code error = boost::asio::error::host_not_found; socket.connect( endpoint, error ); if (error) throw boost::system::system_error(error); int counter = 0; unsigned char* array = new unsigned char[307400]; for (;;) { boost::system::error_code error; ptime startTime = microsec_clock::universal_time(); size_t len = boost::asio::read( socket, boost::asio::buffer( array, 307400 ), boost::asio::transfer_all(), error ); time_duration neededTime = microsec_clock::universal_time() - startTime; if ( error ) { printf( "body read error %s\n", error.message().c_str() ); } if ( counter % 5000 == 0 ) { std::cout << "passed: " << counter << "\r"; } ++counter; if ( neededTime.total_milliseconds() > 1000 ) { std::cout << "ERROR needed too much time: " << neededTime.total_milliseconds() << "ms" << std::endl; } } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } To reproduce the error just let it run for a while. It can take up to 30 minutes or even more... After a while it will produce the line: "ERROR needed too much time: 5007ms". Maybe with slightly different times, but all around 5 seconds. I tested it on different machines with Windows Vista and Seven. So am I'm doing sth. wrong? Is the reading from the socket correct? I'm using boost version 1.44. Kind regards Torben Wiggerich

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De Bruijn Bind (alternate bind syntax) Interest?
by David Sankel 24 Jun '13

24 Jun '13

Hello all, I've been working on an alternate bind syntax based on De Bruijn indices[1]. The syntax is very simple, yet the terms are very powerful. Here is an example of a function const that takes in an argument c and returns another function that, for all input, returns c: //λx.λy.x = λλ1 with De Bruijn indices. auto const_ = abs<1>( abs<1>( var<1,0>() ) ); More examples, further explanation, and an implementation are available here[2]. I'm thinking that this library could also be useful as a core for more syntax heavy bind variations. David [1] http://en.wikipedia.org/wiki/De_Bruijn_index [2] http://bitbucket.org/camior/de-bruijn-bind/ -- David Sankel Sankel Software www.sankelsoftware.com 585 617 4748 (Office)

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[config] consexpr workaround
by vicente.botet 21 Mar '13

21 Mar '13

Hi, in order to make easier the introduction of constexpr in a portable way I would like we add a Boost Config workarround. We can define some macros depending on whether BOOST_NO_CONSTEXPR is defined or not. #if defined(BOOST_NO_CONSTEXPR) #define BOOST_CONSTEXPR #define BOOST_CONSTEXPR_OR_CONST const #else #define BOOST_CONSTEXPR constexpr #define BOOST_CONSTEXPR_OR_CONST constexpr #endif For most of the constexpr functions or constructors BOOST_CONSTEXPR will work. constexpr tuple(); =versus= BOOST_CONSTEXPR tuple(); When used for static constants BOOST_CONSTEXPR_OR_CONST is needed as we need to preserv the const keyword when consexpr is not available. static constexpr UIntType xor_mask = a; =versus= static BOOST_CONSTEXPR_OR_CONST UIntType xor_mask = a; We could also add a STATIC_CONSTEXPR macro #define BOOST_STATIC_CONSTEXPR static BOOST_CONSTEXPR_OR_CONST static constexpr UIntType xor_mask = a; =versus= BOOST_STATIC_CONSTEXPR UIntType xor_mask = a; For this case the existing macro BOOST_STATIC_CONSTANT could be modified to use BOOST_CONSTEXPR_OR_CONST when static const was used. static constexpr UIntType xor_mask = a; =versus= BOOST_STATIC_CONSTANT(UIntType, xor_mask = a); Can we introduce this workaround? Best regards, Vicente _____________________ Vicente Juan Botet Escribá http://viboes.blogspot.com/

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Fwd: [Thread] Solution to conflict with MFC?
by Thorsten Ottosen 28 Feb '13

28 Feb '13

Hi Thread maintainers, Anthony speaks about a patch to make this work. Does anyone know where it is? And could it be applied? Thanks -Thorsten -------- Original Meddelelse -------- Subject: [Thread] Solution to conflict with MFC? Date: Tue, 26 Apr 2011 13:28:56 +0200 From: Christian Larsen <contact(a)dword.dk> Reply-To: boost-users(a)lists.boost.org To: boost-users(a)lists.boost.org Newsgroups: gmane.comp.lib.boost.user Hello, I know this has been asked before, but I could not find a good solution. I'm experiencing problems with an application using both MFC and Boost.Thread. Specifically the assertion ASSERT(AfxGetModuleState() != AfxGetAppModuleState()); in AfxCoreInitModule() fails. I link Boost.Thread statically into a DLL in my project. From previous posts to this list and elsewhere, e.g. http://lists.boost.org/boost-users/2009/04/46929.php, I see that the issue is caused by setting _pRawDllMain in tss_pe.cpp. Commenting this line does "solve" the problem, but I would rather not have to hack the Boost source code this way. It seems there is a patch somewhere for this problem (referred to in http://lists.boost.org/boost-users/2009/04/47015.php) but it appears it never made it into the source. Is there any chance of this issue being solved in a better way? Best regards, Christian Larsen

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[multi_index] Move Semantics
by Mark Snelling 27 Feb '13

27 Feb '13

Hi, I've been a user of Boost.MultiIndex for a number of years and think it's a great library. Is there any firm plan to add move semantics? It's been noted under "Future Work" in the docs since Boost 1.32. Regards, Mark

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[parameter] std proposal
by Lorenzo Caminiti 07 Jan '13

07 Jan '13

Hello all, Is there a C++ standard proposal for named parameter addition? I am looking for an "N-paper" for named parameters similar to N2081 for concepts, or N1962 for contracts. Thank you. -- Sent from my mobile device Lorenzo

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[#pragma once]
by Sid Sacek 18 Nov '12

18 Nov '12

I've worked with the MSVC, Sun and GCC compilers. Each one of them supports #pragma once. Is there any reason to wrap this pragma within #ifdefs? Are there any compilers out there today that don't support this #pragma? #if defined( _MSC_VER ) && ( _MSC_VER >= 1020 ) # pragma once #endif Could we change this coding pattern so that it no longer looks like MSVC is being selfish? -Sid Sacek

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[config] explicit call of operator templates / msvc bug workaround
by Stefan Strasser 10 Oct '12

10 Oct '12

Hi, is there already a macro in Boost.Config that allows you to insert the "template" keyword in the following code for those compilers that require it? struct functor{ template<class T> void operator()(); }; template<class F> void g(F f){ f.template operator()<int>(); //(1) works with GCC and comeau f.operator()<int>(); //(2) works with MSVC } this apparently only applies to operator calls. MSVC accepts both (1) and (2) for regular functions. (instantiating the operator template with an object of type T as argument, like mpl::for_each does, is not an option. I can't construct T.) thanks, Stefan

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[test] Trunk broken: What happened to test_exec_monitor?
by John Maddock 21 Sep '12

21 Sep '12

Testing on Trunk is apparently broken as the test_exec_monitor target has been removed from Boost.Test Trunk as of revision #74642. A quick grep shows 22 Jamfiles and over 200 targets dependent upon this. Whats happened? John.

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[build] 1.49 unable to bootstrap boost
by yuri kilochek 12 Sep '12

12 Sep '12

Not sure if this goes here. On Windows 7, when I try to do bootstrap on a freshly unzipped boost 1.49 at the root directory, I get the following output: Building Boost.Build engine But that is as far as it gets before os terminates whatever it is doing with this (roughly translated from russian): **** STACK SIZE EXCEEDED **** **** WHILE PERFORMING RECURSION IN BATCH MODE **** Recursion depth=654, Stack usage=90 percent. **** BATCH PROCESSING ABORTED **** Is there a way to build boost bypassing this?

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[type_traits] has_equal_to< std::vector<T> > always true_
by lcaminiti 15 Jul '12

15 Jul '12

-- View this message in context: http://boost.2283326.n4.nabble.com/boost-type-traits-has-equal-to-std-vecto… Sent from the Boost - Dev mailing list archive at Nabble.com.

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hex/unhex()?
by Olaf van der Spek 19 Jun '12

19 Jun '12

Hi, Does Boost have hex/unhex() that support std::string? I can't find them and I think they'd be quite handy to have. -- Olaf

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[Locale] VC11 Regressions
by Joshua Boyce 18 Jun '12

18 Jun '12

I am currently porting some code to the VC11 compiler beta, and as part of that process I ran the unit tests on the libraries I use and noticed some failures in Boost.Locale under VC11 that are not present under VC10. Ones of the tests (test_winapi_collate) actually crashes (showing the WER dialog etc). Logs for comparison (tests were run on trunk): http://dl.dropbox.com/u/74751/cpp/boost/logs/locale-test-vc10-20120330-2143… http://dl.dropbox.com/u/74751/cpp/boost/logs/locale-test-vc11-20120330-2143… Has anyone else observed this or is it a configuration issue on my end?

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status of sp_counted_base_solaris.hpp
by Graham Bennett 07 Jun '12

07 Jun '12

Hi all, I'm interested in getting boost::shared_ptr to use atomic ops on Solaris. I notice there is an implementation using the OS-provided atomics in boost/detail/sp_counted_base_solaris.hpp, but it doesn't seem to be included. According to this thread: http://lists.boost.org/Archives/boost/2006/07/107144.php, it seems the reason might be that it wasn't possible to come up with a proper preprocessor condition to include it on the right versions of Solaris. I'm considering modifying my boost installation to include this header on Solaris - does anyone know of any issues with the code, or can they confirm that it has been well tested? Are there any other reasons for its omission? Thanks, Graham -- Graham Bennett

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[fusion] Trouble using BOOST_FUSION_ADAPT_ADT with boost::fusion::operator<
by GOODHART, TAYLOR 17 May '12

17 May '12

Hi all, I'm attempting to adapt a third-party struct into a fusion sequence using BOOST_FUSION_ADAPT_ADT to get access to a nice operator<. Unfortunately compilation fails and I'm not sure if it's a bug or me using the library incorrectly. As best I can read the error message, it looks like the code is attempting to compare adt_attribute_proxy structs instead of the values represented by these. Below is some code that demonstrates the problem. Can anybody help me out? Thanks, Taylor #include <boost/fusion/adapted/adt/adapt_adt.hpp> #include <boost/fusion/adapted/struct/define_struct.hpp> #include <boost/fusion/adapted/struct/adapt_struct.hpp> #include <set> #include <string> #include <boost/fusion/sequence/comparison/less.hpp> struct test1 { std::string s; const std::string & getS() const { return s; } void setS( const std::string & s_) { s = s_; } }; BOOST_FUSION_ADAPT_ADT( test1, (const std::string &, const std::string &, obj.getS(), obj.setS(val)) ) BOOST_FUSION_DEFINE_STRUCT( , test2, (std::string, s) (int, a) ) struct test3 { std::string s; }; BOOST_FUSION_ADAPT_STRUCT( test3, (std::string, s) ) using boost::fusion::operator<; int main( int argc, char * argv[]) { //Fails /*std::set<test1> destinations1; destinations1.insert(test1());*/ std::set<test2> destinations2; destinations2.insert(test2()); std::set<test3> destinations3; destinations3.insert(test3()); return 0; }

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Latest version and status of lockfree
by Julien Nitard 06 May '12

06 May '12

Hi All, Where can I find the latest version of boost.lockfree ? There's nothing in the sandbox or the vault (it seems). The latest commit on Tim's public git repo was done more than 6 month ago. Now that atomic has been accepted, are there any roadblocks to have boost.lockfree released ? Many thanks, Julien

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[contract] syntax redesign
by Lorenzo Caminiti 04 May '12

04 May '12

Hello all, After a long time of inactivity for Boost.Contract, I am considering how to re-design its macro syntax to make it simpler. I can eliminate a large number of extra parenthesis based on a few pp tricks I've learned in processing Boost.Local's `const bind(type)& var`. Plus, I can provide (optional) support for variadics macros so to use comma-separated pp tuplets instead of parenthesized pp sequences on preprocessors with variadics. For example, I _think_ (but I've not implemented this yet) that I can simplify the syntax like this: #include <contract.hpp> #include <vector> #include "myvector/pushable.hpp" // Wrapper class that adds contracts to std::vector. CONTRACT_CLASS( template( typename T ) class (myvector) extends( public pushable<T> ) // Subcontracting. ) { CONTRACT_CLASS_INVARIANT( empty() == (size() == 0) // More invariants here (comma separated)... ) CONTRACT_FUNCTION( public void (push_back)( (const T&) element ) precondition( size() < max_size() // More preconditions here (comma separated)... ) postcondition( auto old_size = CONTRACT_OLDOF(size()), // Old value. size() == old_size + 1 // More postconditions here (comma separated)... ) ) { vector_.push_back(element); // Implementation. } // Rest of the class here (with more contracts if needed)... public: typedef typename std::vector<T>::size_type size_type; size_type size(void) const { return vector_.size(); } size_type max_size(void) const { return vector_.max_size(); } bool empty(void) const { return vector_.empty(); } const T& back(void) const { return vector_.back(); } private: std::vector<T> vector_; }; For a side-by-side comparison with N1962 syntax: http://svn.boost.org/svn/boost/sandbox/contract/libs/contract/doc/html/inde… For a comparison of the entire std::vector (plus Boost.ConceptCheck concepts): http://svn.boost.org/svn/boost/sandbox/contract/libs/contract/doc/html/cont… For a comparison for all Boost.Contract features (plus Boost.ConceptCheck concepts and Boost.Parameter named parameters): http://svn.boost.org/svn/boost/sandbox/contract/libs/contract/doc/html/cont… (Don't pay attention to the rest of the docs that are way out of date.) A few notes: * Extra parenthesis are still needed around class and function names. * Extra parenthesis are still needed around types (like for the parameter `(T) element`) but only if the type is not a C++ keyword (no parenthesis needed aournd int, double, void, etc) or it contains a symbol (parenthesis needed if & or * are used `(int&) x`, etc). * In postconditions, the `auto old_size = CONTRACT_OLDOF(size())` only copies the vector size (and not the entire vector :)) ). Similarly, `auto result = return` can be used to access the return value for non-void functions. (The `auto ...` is parsed by the pp and it's implemented using Boost.Typeof so no C++0x is required.) * Template declaration (but not instantiation) angular parenthesis <> are replaced by round parenthesis (). All of this _should_ be implementable in pure ISO C++. What do you think? Based on the discontent that the previous "parenthesized" syntax generated among Boosters, the key question is: Would you consider this new syntax usable?? Thanks, --Lorenzo

5 45

Review request: extended complex number library
by Matthieu Schaller 02 May '12

02 May '12

Dear all, Following the comments from V. Escriba, I formally propose my complex number library for review. The library is an extension of the std::complex class addressing two issues: - The standard does not guaranty the behaviour of the complex class if instantiated with types other than float/double/long double. - Some calculation where pure imaginary numbers (i.e. multiples of sqrt(-1)) appear are unnecessarily slowed down due to the lack of support for these numbers. The code I submit contains two interleaved classes boost::complex and boost::imaginary which can be instantiated with any type T provided T overloads the usual arithmetic operators and some basic (real) mathematical functions depending on which complex function will be used. It is thus an extended version of Thorsten Ottosen's n1869 proposal (http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1869.html) Performance tests show some non-negligible speed-ups compared to std::complex for calculations where pure imaginary numbers are involved. A speed-up of 25% has been observed when solving the Schroedinger equation explicitly on a regular mesh and some comparable figures can be observed when computing the Mandelbrot set (the two examples snippets provided in the archive). Furthermore, the functions (sin(), exp(), log(),...) involving boost::imaginary numbers are more precise than their equivalent using a std::complex with the real part set to 0. The code and (doxygen) documentation is available in the repository http://code.google.com/p/cpp-imaginary-numbers/ A comprehensive zip archive can be found in the "download" and the code can also be checked-out via the SVN repository. The archive contains the class header, two examples, a comprehensive precision test, a brute-force performance test and the documentation. I'd be happy to answer any question from your side and to provide more detailed information if required. Regards, Matthieu -- Matthieu Schaller PhD student - Durham University

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Re: [boost] Slow Bugs Tracker
by Olaf van der Spek 29 Apr '12

29 Apr '12

Hi, A few months ago there seemed to be plans to improve Trac. What's the status of those plans? Trac is still slow as hell. http://lists.boost.org/Archives/boost/2011/12/188639.php http://lists.boost.org/Archives/boost/2011/12/188937.php -- Olaf

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Boost.ntree_container (bi_tree, quad_tree, oct_tree, etc ptr containers) Is there any interest in this?
by Dan Walters 27 Apr '12

27 Apr '12

Hi all, I am proposing adding spacial containers for efficiently storing and accessing data of a spacial nature in fixed size trees. n-tree data structures would be useful where data relates to a 1D, 2D or 3D location, providing n-array searching of an n-array volume. N-tree data structures are commonly used in 3d applications, and are rarely particularly specialized. Their use is fundamental however they are frequently written by application programmers, due to a lack of free open source implementations (to the limit of my research). Their sophistication, like any container, is slim but easy to get wrong and beyond the ability and time contraints that should be assumed of the application programmer. It is a flexible and standard enough concept that a single implementation can be expected to meet a majority of requirements. I think there is the opportunity to create a solid implementation of templated n-tree pointer containers. The ntree container would be a tree representing an narray of elements with all dimensions being the same and being a power of two. The tree is memory efficient where areas within the volume are not occupied, and so "branches" and "leaves" are not created. The tree is well suited to geometrical operations such as ray picking or plane culling of the volume. An n-tree structure could be used in the place of any sparely populated n dimensional array where memory saving is the objective. The existing libraries I have found are licensed under GNU licenses. A ntree container should implement: get reset overloaded (array style) operators Optional implementations: views - a subset object representing an area or volume within the tree for accelerated access to a group of leaves that are positioned near to each other raycasting plane culling (getting leaves within a set of planes) etc. Is there interest in such a library? Many thanks, Dan

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[result_of] Make `cpp0x_result_of_impl` public
by Michel Morin 26 Apr '12

26 Apr '12

There are two implementations of boost::result_of: a TR1-style implementation and a decltype-based implementation. While the TR1-style implementation has a public interface `boost::tr1_result_of`, decltype-based one doesn't have a public interface. By defining BOOST_RESULT_OF_USE_DECLTYPE, boost::result_of use decltype-based implementation. But this is not always a viable solution, since this breaks some Boost libraries. So how about adding `boost::cxx11_result_of` as public interface of the decltype-based implementation? Attached a patch to add `boost::cxx11_result_of`. (This patch also changes the name of `cpp0x_result_of_impl` to `cxx11_result_of_impl` to reflect the recent discussion on the cpp/cxx naming.) P.S. Is it worth trying to use this `boost::cxx11_result_of` in `boost::transform_iterator` code on trunk? Regards, Michel

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[quickbook] controlling table of contents
by lcaminiti 14 Apr '12

14 Apr '12

Hello all, Is there a way for more fine control of QuickBook table of contents (toc)? Specifically, I'd like to: 1) Have a toc in the first page with only the sections (no subsections) listed. 2) Then, have a full toc on the second documentation page with all sections and subsections listed. I can use any rev of QuickBook for this. Thanks a lot. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-quickbook-controlling-table-of-con… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[typeof] registration question
by Cromwell Enage 14 Apr '12

14 Apr '12

Hi, folks! In emulation mode, given the following definition: template <typename Container> struct some_metafunction { typedef BOOST_TYPEOF_TPL( Container().insert( typename Container::iterator() , typename Container::value_type() ) ) type; }; Which of the following types need to be registered? 1. The argument passed as `Container` 2. The result of `typename Container::iterator` 3. The result of `typename Container::value_type`

3 7

[lockfree] tagged_ptr as a separate library
by Philipp Moeller 12 Apr '12

12 Apr '12

In the review of lockfree it has been suggested that tagged_ptr should make it into the public API of lockfree. Wouldn't it make sense to move it into a separate library entirely? It would possibly get more exposure and cross-platform ports. The technique itself also requires some extra documentation. And it might find it's way into a release earlier than lock-free itself. Philipp Moeller

5 7

[range] adaptors vs. rvalue to lvalue& binding
by Arno Schödl 11 Apr '12

11 Apr '12

Hello, ideally I would like to use range-adapted lvalue ranges like any other lvalue ranges. Writing it down naively, as below, does not compile because LoadRefRange takes (and should take?) the range it modifies by lvalue&, while adaptor expressions are rvalues. template<typename Range> void modifies_range( Range& rng ); A a[5]; main() { // modifies all elements of a modifies_range ( a ); // modifies all elements (except for one) of a // adaptor is rvalue, does not compile: modifies_range ( boost::range::join( boost::adaptors::slice( a, 0, 1 ), boost::adaptors::slice( a, 2, countof(a) ) ) ); // compiles, but ugly: auto rng=boost::range::join( boost::adaptors::slice( a, 0, 1 ), boost::adaptors::slice( a, 2, countof(a) ) ); modifies_range(rng); } Any thoughts? Should adaptors receiving lvalues offer an operator adaptor&() &&; // overload on rvalue-ness so they are passing through the lvalue or their argument? A suitable baseclass a la boost::additive could do that. Regards, Arno -- Dr. Arno Schödl | aschoedl(a)think-cell.com Technical Director think-cell Software GmbH | Chausseestr. 8/E | 10115 Berlin | Germany http://www.think-cell.com | phone +49 30 666473-10 | US phone +1 800 891 8091 Amtsgericht Berlin-Charlottenburg, HRB 85229 | European Union VAT Id DE813474306 Directors: Dr. Markus Hannebauer, Dr. Arno Schoedl

8 21

[config] unexpected explicit operators conversion on some compilers.
by Vicente J. Botet Escriba 10 Apr '12

10 Apr '12

Hi, Given the following explicit bool conversion template<typename Mutex> class unique_lock { public: explicit operator bool() const BOOST_NOEXCEPT I was expecting the following code to compile fail (note the int cast) boost::unique_lock<boost::mutex> lk0; int i = int(lk0); It fails with gcc-4.7.0, but compile with gcc-4.6.2 and clang-3.0 (I have not tested yet with msvc). When BOOST_NO_EXPLICIT_CONVERSION_OPERATORS is defined I use the bool safe idiom to emulate the conversion #if defined(BOOST_NO_EXPLICIT_CONVERSION_OPERATORS) typedef void (unique_lock::*bool_type)(); operator bool_type() const BOOST_NOEXCEPT; bool operator!() const BOOST_NOEXCEPT; #else explicit operator bool() const BOOST_NOEXCEPT; #endif and in this case the compile fail as desired. Do we need a new macro to state that even if explicit operators are provide, there are some unexpected conversions that could be introduced? Best, Vicente

1 1

Release branch open for new libraries?
by Marshall Clow 10 Apr '12

10 Apr '12

When will the release branch be open for new libraries (for 1.50)? The calendar on Boost.org shows no dates for 1.50 at all. Thanks! -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

3 8

[scope_exit] trunk tests fail on sun compiler
by lcaminiti 09 Apr '12

09 Apr '12

Hello all, I'm trying to get ScopeExit to work on Sun. 1) First it looked like all tests fail on this compiler: http://www.boost.org/development/tests/trunk/developer/scope_exit.html 2) However, I installed Solaris Studio 12.3 on my Ubuntu 10 and it seems that I can compile ScopeExit just fine with the following" $ CC -I /usr/include/i386-linux-gnu/ -I ../../.. -DBOOST_TYPEOF_EMULATION world_seq.cpp Note that: a) Sun does not support variadic macros so only ScopeExit sequence syntax will work. b) Sun does not support native type-of so BOOST_TYPEOF_EMULATION needs to be defined. Therefore, all original ScopeExit type-of emulation tests named `emulation_...` should compile (because they use the sequence syntax and define BOOST_TYPEOF_EMULATION). However, they fail... why? 3) Why when I click on the "fail" link for these tests I get no information on the Sun compiler's output? For example: http://www.boost.org/development/tests/trunk/developer/output/Sandia-sun-bo… If I follow this link I get "Error extracting file: No matching files were found.". What does this mean? Thanks a lot! --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-scope-exit-trunk-tests-fail-on-sun… Sent from the Boost - Dev mailing list archive at Nabble.com.

6 34

Nightly testing broken due to missing file
by Belcourt, K. Noel 07 Apr '12

07 Apr '12

error: Unable to find file or target named error: './sync/mutual_exclusion/locks/upgrade_lock/cons/ move_ctor_shared_lock_until_pass.cpp' error: referred from project at error: '../libs/thread/test'

3 2

[signals] [vc11] Compile Error (Ticket #1499)
by Joshua Boyce 04 Apr '12

04 Apr '12

The problem causing ticket #1499 is happening again under VC11. https://svn.boost.org/trac/boost/ticket/1499 Build scripts and logs: http://dl.dropbox.com/u/74751/cpp/boost/logs/msvc32-20120319-1118.bat http://dl.dropbox.com/u/74751/cpp/boost/logs/msvc64-20120319-1118.bat http://dl.dropbox.com/u/74751/cpp/boost/logs/msvc32-20120319-1118.txt http://dl.dropbox.com/u/74751/cpp/boost/logs/msvc64-20120319-1118.txt Bumping to check for _MSC_VER <= 1700 does the trick (tested locally). Patch: http://dl.dropbox.com/u/74751/cpp/boost/patches/signals-vc11-fix-20120319-1… Once this is applied the trunk compiles cleanly (well, no errors, there are still lots of warnings) using the VC11 beta. Thanks.

2 3

[git] Mercurial?
by Daryle Walker 02 Apr '12

02 Apr '12

Git has a competitor called Mercurial? If we're moving to a Distributed-VCS, should we go to Mercurial instead of Git? They're kind-of like CVS vs. Subversion, except I think they came up in parallel. (While Subversion was designed as an updated CVS.) I think Git was made up of a bunch of script hacks, while Mercurial was a regimented single program. I don't have a preference, but I want to make sure we consider the rival options. Daryle W.

48 236

[test] Use of namespace qualifier before floating point functions in boost/test/impl/execution_monitor.hpp
by Jeremiah Willcock 02 Apr '12

02 Apr '12

According to http://pubs.opengroup.org/onlinepubs/009604599/basedefs/fenv.h.html, operations such as feclearexcept can be defined as macros, and at least some versions of Glibc do that by default. The use of explicit :: qualifiers before calls to those in Boost.Test fails to compile. Is there a workaround for that (other than __NO_MATH_INLINES)? -- Jeremiah Willcock

1 1

[quickbook] coloring code syntax
by lcaminiti 02 Apr '12

02 Apr '12

Hello all, Is there a way to tell QuickBook code fragments to color words that are not C++ keyword for example in blue or in other colors? For example, in `int i = 0;` "int" is colored in blue. I'd like that in `requires Copyable<T>` "requires" is colored in blue (or some other color that I can specify). Thanks a lot! --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-quickbook-coloring-code-syntax-tp4… Sent from the Boost - Dev mailing list archive at Nabble.com.

3 2

[result_of] Test fails on clang trunk and gcc-4.7 due to changes in FDIS
by Michel Morin 01 Apr '12

01 Apr '12

In the code below, const int f(); decltype(f()) i = 0; `i` has type `int` (not `const int`) in C++11. This is because `f()` is a prvalue of a non-class type (i.e. `const int`) and so its cv qualifiers are ignored. C++0x drafts (before FDIS) had a special rule for function calls in decltype: if e is a function call or an invocation of an overloaded operator (parentheses around e are ignored), decltype(e) is the return type of the statically chosen function; but this was removed in FDIS. Clang-3.1 (which will be clang-3.1) and gcc-4.7 seem to have implemented this change, and this change breaks the test case (libs/utility/test/result_of_test.cpp) on those compilers in a C++11 mode. The following are the errors messages: [1] result_of_test.cpp:210:3: error: static assertion failed: (is_same<result_of<const result_of_member_function_template(double)>::type, const double>::value) [2] result_of_test.cpp:211:3: error: static assertion failed: (is_same<result_of<volatile result_of_member_function_template(double)>::type, volatile double>::value) [3] result_of_test.cpp:212:3: error: static assertion failed: (is_same<result_of<const volatile result_of_member_function_template(double)>::type, const volatile double>::value) [4] result_of_test.cpp:239:3: error: static assertion failed: (is_same<result_of<const volatile no_result_type_or_result_of(void)>::type, const unsigned short>::value) [5] result_of_test.cpp:244:3: error: static assertion failed: (is_same<result_of<const volatile no_result_type_or_result_of_template<void>(void)>::type, const unsigned short>::value) Regards, Michel

3 10

Status of proposed boost.overload?
by niXman 01 Apr '12

01 Apr '12

Hello list! boost.overload: http://svn.boost.org/svn/boost/sandbox/overload/ The library will be accepted into the boost libraries ? -- Regards, niXman

5 11

[container][memory] Request to move allocator_arg_t and uses_allocator to a memory related file.
by Vicente J. Botet Escriba 31 Mar '12

31 Mar '12

Hi, I want to add Allocators to the packaged_task and promise class of Boost.Thread template <class Allocator> promise(allocator_arg_t, const Allocator& a); template <class F, class Allocator> explicit packaged_task(allocator_arg_t, const Allocator& a, F&& f); I see that Boost.Container has already defined in namespace boost::container and in file boost/container/scoped_allocator.hpp the following struct allocator_arg_t { }; constexpr allocator_arg_t allocator_arg = allocator_arg_t(); template <class T, class Alloc> struct uses_allocator; I would like to shared these to all the Boost libraries. I don't think it is a good idea to make Boost.Thread depend on Boost.Container just for this. Could these declarations be included in a specific file? These declaration are included in <memory> in the C++11. What would be the best library to contain these declarations? What about a new boost/memory.hpp file? What about moving them to the boost or boost::memory namespace? Best, Vicente

2 5

[offtopic] C++Now! Room Reservation at Aspen Meadows
by Hartmut Kaiser 31 Mar '12

31 Mar '12

Hey all, If somebody needs a room reservation at the Aspen Meadows for C++Now in May, please get in contact with me offline. I have to cancel my trip and would like to avoid the cancellation penalty for my booked room. Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

1 0

[guideline] 31 character filenames?
by Eric Niebler 30 Mar '12

30 Mar '12

Our current guidelines[1] say filenames should not exceed 31 characters. This was recently brought to my attention by a bug[2] from someone who actually cares because he uses the ODS-2 filesystem on OpenVMS. On a lark, I hacked the inspect tool to check for too-long filenames and lo! found a bazillion. Most (but not all) violations are from doc files auto-generated by doxygen and docbook, but which nevertheless go out with the boost distribution and so should conform. (Right?) So, should we care? Considering that we have little control(?) over how doxygen and docbook generate their files? I have fixed the bug in question, but it feels like a token effort. Should we just drop support for niche filesystems like ODS-2, and close all future bugs "won't fix"? [1] http://www.boost.org/development/requirements.html [2] https://svn.boost.org/trac/boost/ticket/6196 -- Eric Niebler BoostPro Computing http://www.boostpro.com

10 14

[Assign][GIL] Boost Assign and GIL incompatibility in gcc 4.3.2
by Andrew Hundt 29 Mar '12

29 Mar '12

The following source code compiles under clang 3.1, but fails under gcc 4.3.2 with boost version 1.46. It doesn't look like there are updates to either library in the boost news list since then. #include <vector> #include <boost/assign/std/vector.hpp> // for 'operator+=()' #include <boost/gil/gil_all.hpp> int main(int argc, char** argv){ using namespace boost::assign; std::vector<int> values; values += 1, 2, 3, 4; typedef boost::gil::rgb8_pixel_t pt; std::vector<pt> pixValues; pixValues += pt(1,2,3),pt(2,3,4); } ------------------------------------- Compiler versions: FAILED: gcc (SUSE Linux) 4.3.2 [gcc-4_3-branch revision 141291] Copyright (C) 2008 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. SUCCEEDED: Apple clang version 3.1 (tags/Apple/clang-318.0.54) (based on LLVM 3.1svn) Target: x86_64-apple-darwin11.3.0 Thread model: posix Cheers! Andrew Hundt

3 3

Arena/Linear allocators
by Olaf van der Spek 29 Mar '12

29 Mar '12

Hi, I'm looking for arena/linear allocators, for use with multi_index, unordered_map and others. Does Boost provide anything like this? There's Boost Pool, but it only provides a singleton pool allocator. -- Olaf

2 2

[contract] nothing special about nested classes
by lcaminiti 29 Mar '12

29 Mar '12

Hello all, In the _many_ Contract Programming references that I have read (including N1962): http://contractpp.svn.sourceforge.net/viewvc/contractpp/trunk/doc/html/cont… I didn't find anything special about contracts for nested classes. I think that is because nested classes are executed at run-time "orthogonally" with respect to their enclosing classes. In other words, nesting a class only nests it's name (and changes some visibility rules) but it does not effect the run-time execution of the class and therefore it does not affect the contracts checked for the nested class. For example, the execution of a nested class y should only check y's invariants and not also the invariants of its enclosing class x: #include <contract.hpp> #include <iostream> CONTRACT_CLASS( struct (x) // enclosing class ) { CONTRACT_CLASS_INVARIANT( std::cout << "x's invariant" << std::endl ) CONTRACT_CLASS( public struct (y) // nested class ) { CONTRACT_CLASS_INVARIANT( std::cout << "y's invariant" << std::endl ) CONTRACT_FUNCTION( public void (f) ( void ) ) {} }; }; int main ( void ) { x::y yy; yy.f(); // checks y's invariant but not x's invariant return 0; } In fact in this example an object of x is not even created. Of course, if y was to create or get an object of x and invoke x's member functions then x's contracts will be checked as usual. This makes sense to me but I thought to share it with the ML. Thanks. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-contract-nothing-special-about-nes… Sent from the Boost - Dev mailing list archive at Nabble.com.

1 0

Boost Optional
by Rafael Justo 29 Mar '12

29 Mar '12

Hello! This is my first post in this list. =) I was looking today at Boost Optional (great work!). And I was wondering how could I do something like the bellow code. -------------------------------- #include <boost/optional.hpp> class Test {}; boost::optional<Test> get() { return boost::optional<Test>(); } int main() { if (get() == true) { // OK } else if (get() == false) { // ERROR } return 0; } -------------------------------- But there's no "operator==" with bool in optional.hpp, so the above code don't compile (i have checked version 1.49). Is it possible to add the patch described bellow in optional.hpp to solve this problem? -------------------------------- --- boost_1_49_0/boost/optional/optional.hpp 2010-12-18 19:29:39.000000000 -0200 +++ boost_1_49_0_new/boost/optional/optional.hpp 2012-03-28 16:03:53.417578997 -0300 @@ -616,6 +616,11 @@ return *this ; } + bool operator== (const bool condition) + { + return ((*this && condition) || (!*this && !condition)); + } + void swap( optional & arg ) { // allow for Koenig lookup -------------------------------- Best regards, Rafael Justo

4 4

using of circular_buffer
by news.gmane.org 28 Mar '12

28 Mar '12

Hello there, i am new here and i just want to say "hi". so, i'm using boost almost a year now, usually i just used the array component. latley i wanted to implement the circular_buffer. i've defined it in a class after the private-modifier like this: boost::circular_buffer<std::string> textBuffer(10); (as take from the documentation) but my compiler on minGW will throw an error. so, i guess i got something wrong in declaring a string-textbuffer with the lenght of 10?! in the boost-docs there is following example: boost::circular_buffer<int> cb(3); help is appreciated, best would be a working example and a little hint which information is may have missed. greetings tony

3 4

Fwd: [Boost-bugs] [Boost C++ Libraries] #380: Support for bundled properties in graph adaptors
by Marshall Clow 28 Mar '12

28 Mar '12

I just wanted everyone to notice that Jeremiah just closed a _seven year old_ bug in boost. -- Marshall Begin forwarded message: > From: "Boost C++ Libraries" <noreply(a)lists.boost.org> > Subject: Re: [Boost-bugs] [Boost C++ Libraries] #380: Support for bundled properties in graph adaptors > Date: March 28, 2012 1:47:03 PM PDT > Cc: boost-bugs(a)lists.boost.org > Reply-To: boost(a)lists.boost.org > > #380: Support for bundled properties in graph adaptors > -----------------------------------+---------------------------------------- > Reporter: dgregor | Owner: dgregor > Type: Bugs | Status: closed > Milestone: To Be Determined | Component: graph > Version: Boost Release Branch | Severity: Problem > Resolution: wontfix | Keywords: > -----------------------------------+---------------------------------------- > Changes (by jewillco): > > * status: reopened => closed > * resolution: => wontfix > > > Old description: > >> {{{ >> The graph adaptors (such as subgraph) do not support bundled >> properties, but they should. >> }}} > > New description: > > {{{ > The graph adaptors (such as subgraph) do not support bundled > properties, but they should. > }}} > > -- > > Comment: > > This is likely to work now, so closing as wontfix. Please reopen if the > problem still exists in the trunk version of Boost. > > -- > Ticket URL: <https://svn.boost.org/trac/boost/ticket/380#comment:7> > Boost C++ Libraries <http://www.boost.org/> > Boost provides free peer-reviewed portable C++ source libraries. > _______________________________________________ > Boost-bugs mailing list > Boost-bugs(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-bugs -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

2 1

DCVS vs CVS: call for constructivism
by Philippe Vaucher 28 Mar '12

28 Mar '12

Hello, I think we all know understood that there are people from both camps, some with emotional arguments, some with constructive arguments, but it's not really moving anywhere. We need to start listing what would have to be done and once we have such a map see if it's worth it before discussing pointless things. Just so we can redirect people saying things like "Nobody told me a real advantage yet" to this post, here's a recapitulation of what I think the advantages/disadvantages of a DCVS is ( http://www.ericsink.com/vcbe/html/dvcs_advantages.html, http://www.ericsink.com/vcbe/html/dvcs_weaknesses.html) Pro: - Offline work (you can use diffs, you can commit) - Speed of operations compared to svn - No need to setup a server to work locally (encourages participation (focus on working first, then sharing later)) Cons: - Cannot check out subpaths - Cannot lock files - Would require people to change their habits and learn new tools I think most people in the svn-camp will tell that with the 1.8 checkpoints feature you can now also commit while offline and thus the only advantages for DCVS seems to be speed and the ability to check all the data while offline. I think the people that are opposed to the change unfortunately won't be convinced by those arguments, even tho pretty much every who switched to DCVS will tell you that the advantages are worth it and it's more than simply speed or freedom, it's a philosophy etc. So I think the best thing to do now is first to make a map of what would have to be done if we decided to switch, to see if it's an option at all. Here's a simple draft, please participate into making it better: - Import current history - Migrate the existing hooks - Migrate the existing scripts around. - Migrate the test runners - Trac / Website integration (redmine with git extensions?) - Rights management (gitolite?) - Update release procedures Maybe we'd start a page on the wiki, but the idea is to find out if there are more steps to be done and if there's any showstopper in those steps. I think the best solution would be to offer the repository with several protocols, namely git/hg/svn so everyone could use the tool they want (e.g github offers svn/git, I know other hosts do it too). Philippe

10 19

[Lockfree] Small compilation error with gcc -Wall
by Julien Nitard 28 Mar '12

28 Mar '12

Hi all, The following code seems to generate an "unused variable" variable warning with g++ -Wall. I am working on the latest version available from git, though I am not sure if this version is relevant. #include <boost/lockfree/fifo.hpp> typedef boost::lockfree::fifo<ReplicateData, boost::lockfree::static_freelist_t> Queue; Queue _buffer(4096); It occurs in fifo.hpp at line 263. Replacing tagged_node_ptr head2 = head_.load(memory_order_relaxed); By head_.load(memory_order_relaxed); Seems to do the job. Many thanks, Julien

2 1