May 2005 - Boost - lists.preview.boost.org

[variant, MPL] Is there a variant -> mpl sequence metafunction ?
by Jaakko Järvi 13 Nov '06

13 Nov '06

make_variant_over<Seq>::type creates a variant type from an MPL Sequence. Is there an operation that would do the opposite, create an MPL sequence from a variant? I cannot just use the type parameter list as such because the types that stand for an empty type are different in both libraries: boost::detail::variant::void_ in variant, and something else in MPL. Best, Jaakko -- Jaakko Järvi, jarvi(a)cs.tamu.edu

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[jamboost] Boost.Build V2, Milestone 10 released
by Vladimir Prus 04 Nov '06

04 Nov '06

I'm pleased to announce that the next milestone release of Boost.Build V2 is available at http://prdownloads.sourceforge.net/boost/boost-build-2.0-m10.tar.bz2 http://prdownloads.sourceforge.net/boost/boost-build-2.0-m10.zip See also http://boost.org/boost-build2/ for online docs (a copy is included in distribution). Due to large number of improvements all users are encouraged to upgrade. Changes in this release: Many toolsets were added: Intel, Metrowerks, Comeau, aCC, vacpp. Documentation was converted to BoostBook and improved. Performance was improved. - Toolsets initialization syntax is much more uniform. Compiler and linker flags can now be specified. - The algorithm for computing build properties was improved. Conditional requirements can be chained, and a number of bugs were fixed. - Specific order of properties can be specified. - The main target rules can be called from everywhere, not necessary from Jamfile. - Check for "unused sources" removed. - The <library> feature affects only linking now. - The <file> feature now works only for libraries. - Simpler syntax for "searched" libraries was added. - New <dependency> feature. Unix: The right order of static libraries on Unix is automatically computed. The <hardcode-dll-paths> feature is the default. gcc: The -fPIC option is passed when creating shared libraries. Problems with distcc were solved. Sun: It's now possible to use the sun linker (as opposed to gnu), and to compile C files. Darwin: Shared libraries are now supported. MSVC: Before resource files compilation, the setup script is invoked. Options deprecated in 8.0 are not longer used. The following bugs were fixed: - The <unit-test> rule did not handle the <library> property. - Don't add "bin" to the build directory explicitly specified by the user. - Allow <include-type> to select staged targets, even with <traverse-dependencies>off. - Includes for the form '# include <whatever>" did not work. - (Qt) Add paths to all dependent libs to uic command line, which helps if the UI files uses plugins. - Using <toolset-msvc:version>xxx in requirements was broken. - Error message printed when target can be found is much more clear. - Inline targets in sources of 'stage' did not work. - Don't produce 'independent target' warnings on Windows - (gcc) The <link-runtime>static did not work. - (gcc) Suppress warnings from the 'ar' tool on some systems. - (gcc) Don't try to set soname on NT. Developer visible changes: - Generator priorities are gone, explicit overrides are used. - 'Active' features were removed - Support for VMS paths was added. Thanks to Christopher Currie, Pedro Ferreira, Philipp Frauenfelder, Andre Hentz, Jurgen Hunold, Toon Knapen, Johan Nilsson, Alexey Pakhunov, Brock Peabody, Michael Stevens and Zbynek Winkler who contributed code to this release. - Volodya

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[Python] Slice test fails on Intel 8.1 at runtime
by Stefan Slapeta 23 Oct '06

23 Oct '06

This is not a new failure, but the failure is reported for the first time. Please could anybody have a look at it? See http://tinyurl.com/4n2fx Thanks, Stefan

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TR2 and C++0x heads up
by Beman Dawes 23 Sep '06

23 Sep '06

The C++ standards committee's Library Working Group has proposed a schedule for library changes and extensions: * October 2005: cutoff date for C++0x major library proposals * October 2006: cutoff date for library TR2 proposals * April 2007: cutoff date for C++0x library clean-up papers The usual rule-of-thumb is that new library components go in TR2, while changes to existing components go in C++0x. The LWG will consider exceptions to the rule on a case-by-case basis. The LWG is planning to issue a "Call for Proposals" with details, but in the meantime Boost developers might want to start thinking about which Boost libraries they want to propose to the LWG. Because most proposals go through one or more revisions before being accepted, it helps a proposal's chances if it reaches the committee as many meetings as possible before the final cut-off. So far there are plans to propose Boost.Threads, Boost.Filesystem, and Boost.Signals. As well as proposals for some of the more major libraries, I personally hope someone will do a sweep through Boost looking at some of the smaller utilities and helpers for a possible "Small Additions" proposal. --Beman

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New implementation of remove_xxx for vintage compilers
by Peder Holt 28 Mar '06

28 Mar '06

Hi. I have started implementing some of the missing type_traits functionality for vintage compilers using typeof. The following are complete, and seem to work flawlessly on VC 6.5 and 7.0: remove_pointer remove_reference remove_bounds The source is available at: http://groups.yahoo.com/group/boost/files/typeof_vintage.zip The use of typeof in this respect, makes remove_xxx much more flexible. Would it be possible to start using this scheme for compilers without partial template specialization support? #define BOOST_MAX_TYPEOF_SIZE 20 #include <boost/test/minimal.hpp> //Include typeof_define.hpp in all header files where new types are added to typeof. #include <boost/typeof/typeof_define.hpp> #include <complex> #include <boost/type_traits/remove_reference.hpp> #include <boost/type_traits/remove_pointer.hpp> #include <boost/type_traits/remove_bounds.hpp> #include <boost/type_traits/is_same.hpp> template<typename A0> struct X {}; template<typename A0,unsigned int A1> struct Y {}; template<typename A0,typename A1,long A2> struct Z {}; BOOST_TYPEOF_DEFINE_TEMPLATE(X,1,(typename)) BOOST_TYPEOF_DEFINE_TEMPLATE(Y,2,(typename,unsigned int)) BOOST_TYPEOF_DEFINE_TEMPLATE(Z,3,(typename,typename,long)) BOOST_TYPEOF_DEFINE_TEMPLATE(std::complex,1,(typename)) int test_main(int, char*[]) { BOOST_TEST((boost::is_same<X<int>* const[8][9],boost::remove_bounds<X<int>* const[5][8][9]>::type>::value)); BOOST_TEST((boost::is_same<Z<X<double&>,Y<bool[4][7],12324>,0>* const*,boost::remove_pointer<Z<X<double&>,Y<bool[4][7],12324>,0>* const**volatile>::type>::value)); //VC7.1 fails to compile remove_reference. BOOST_TEST((boost::is_same<Y<int,345>** const,boost::remove_reference<Y<int,345>** const&>::type>::value)); typedef BOOST_TYPEOF(5.+std::complex<double>(6,7)) result_type; BOOST_TEST((boost::is_same<result_type,std::complex<double> >::value)); return 0; } -- Peder Holt

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[ANN] Phoenix-2 Preview
by Joel de Guzman 01 Dec '05

01 Dec '05

Hi, Hi. Here's a preview of Phoenix V2. This will probably be the last release of the library. Phoenix V2 will be the basis of the Phoenix and Boost.Lambda merger. You can get it here: http://spirit.sourceforge.net/dl_more/phoenix-2.zip You can browse the draft docs here: http://tinyurl.com/6crgp What's new? A lot. This is a total rewrite based on earlier discussions with Jaakko Jarvi. The library's is built on top of Fusion and of course MPL. Of particular interest are local variables and lambda-lambda scopes: http://tinyurl.com/3mn6w There is also a set of lazy functions that work on STL sequences (e.g. push_back etc.): http://tinyurl.com/46bbm and pretty soon, a final TODO item (built on top of scopes/ lambda), lazy STL algorithms (e.g. find_if, etc). The scopes section (link provided above) in the docs illustrates how to write lazy functions that accept higher order functions (e.g. for_each). Regards, -- Joel de Guzman http://www.boost-consulting.com http://spirit.sf.net

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policy_ptr?
by Peter Dimov 16 Aug '05

16 Aug '05

The recent lively thread in comp.lang.c++.moderated has sparked my interest in the policy_ptr proposal. Is the final version of the submission available? -- Peter Dimov http://www.pdimov.com

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[Random] Mersenne Twister initialization problem [PATCH]
by Tiago de Paula Peixoto 21 Jul '05

21 Jul '05

Hi. The Mersenne Twister RNG was updated by the original author in 2002, because of a small problem in the seeding procedure, which was that the most significant bit of the seed was not well reflected to the state vector. Read http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/emt19937ar.html for more details. The version implemented in Boost is the original 1998 one, which contains the problem. The attached patch implements the new seeding procedure, which uses something different than the linear congruential RNG to initialize the state vector. I haven't identified the new procedure to match any generator already implemented in Boost, so I just wrote it there (please correct me if I'm wrong). I have compared the output to the official implementation output, and it's identical. If the patch is OK, could it be applied? Thanks. -- Tiago de Paula Peixoto <tiago(a)forked.de>

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[regex] regex_replace with format string replaced as it is
by Lorenzo Bettini 14 Jul '05

14 Jul '05

Hi when I use template <class traits, class Allocator, class charT> basic_string<charT> regex_replace(const basic_string<charT>& s, const basic_regex<charT, traits, Allocator>& e, const basic_string<charT>& fmt, match_flag_type flags = match_default); is there a way to make the fmt string be substituted as IT is? I mean if I specify "(\\)", for instance, I want that actually those four characters to be substituted for the occurrences of e in s, without any interpretation of ( and \. Of cource I could escape both ( and \, but I was wondering if there's an option to avoid this. thanks in advance Lorenzo

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BOOST_NO_RESULT_OF
by David Abrahams 13 Jul '05

13 Jul '05

I want this macro for the parameters library. Currently, result_of uses #if !defined(BOOST_NO_SFINAE) && !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) And otherwise, gives an #error That makes it hard to use portably, because the criteria under which result_of will be supported are not encapsulated, and I couldn't even define it in that file usefully (I'd still get an #error when it isn't supported). Shouldn't there be a generalized way to handle this sort of situation? -- Dave Abrahams Boost Consulting www.boost-consulting.com

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