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namespace naming -- the question to moderators
by Arkadiy Vertleyb 10 Apr '06

10 Apr '06

Hi all, The typeof library defines some templates in the unnamed namespace. This was done to avoid ODR violations in certain contexts (although it introduces them in other contexts). The unnamed namespace used now is: boost::type_of::<unnamed> It turnes out MSVC 7.1 and 8.0 cannot handle this kind of namespace correctly in conjunction with precompiled headers. Specifically, if a template is defined inside such a namespace in the precompiled header, it cannot be specialized outside this precompiled header (for typeof this means types cannot be registered outside pch). The problem can be worked around by using a different kind of unnamed namespace, like, for example: <unnamed>::boost_typeof (<unnamed>::boost::type_of introduces ambiguity in some contexts) This kind of unnamed namespace can be handled correctly by both MS compilers, with respect to pch, but I don't believe it satisfies the Boost naming convention. OTOH, if no other solution is found, this is the only way we can achieve typeof compliance with pch, while still staying in the unnamed namespace. Thoughts? Regards, Arkadiy

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[thread] attribute syntax
by MaximE 09 Apr '06

09 Apr '06

In my home grown POSIX threads wrapper I use expression templates to specify thread, mutex, condition attributes with the following syntax: mutex m(shared | recursive); thread t(..., detached | sched_policy(SCHED_FIFO) | sched_priority(1)); I thought it might be appealing for boost threads library to have something similar. Sketch code follows. #include <pthread.h> #include <memory> // sinposis class error; class thread; template<class T> struct concept; template<class left, class right> struct binary_op; template<class left, class right> binary_op<left, right> operator|(concept<left> const& l, concept<right> const& r); struct detached; struct sched_policy; struct sched_priority; class error : public std::exception { private: char const* s_; int c_; public: error(int code) : s_("thread::error"), c_(code) {} error(char const* s, int c) : s_(s), c_(c) {} int code() const { return c_; } char const* what() const throw() { return s_; } }; #define THREAD_CHK_CALL(call) \ do { \ if(int __thread_error_code__ = (call)) \ throw ::error(#call, __thread_error_code__); \ } while(0) template<class T> struct concept { T const& self() const { return static_cast<T const&>(*this); } }; template<class left, class right> struct binary_op : concept<binary_op<left, right> > { left const& l_; right const& r_; binary_op(left const& l, right const& r) : l_(l), r_(r) {} void apply(pthread_attr_t* a) const { l_.apply(a); r_.apply(a); } }; template<class left, class right> inline binary_op<left, right> operator|(concept<left> const& l, concept<right> const& r) { return binary_op<left, right>(l.self(), r.self()); } struct detached : concept<detached> { detached() {} static void apply(pthread_attr_t* a) { THREAD_CHK_CALL(::pthread_attr_setdetachstate(a, PTHREAD_CREATE_DETACHED)); } } const detached; struct sched_policy : concept<sched_policy> { int policy_; sched_policy(int p) : policy_(p) {} void apply(pthread_attr_t* a) const { THREAD_CHK_CALL(::pthread_attr_setschedpolicy(a, policy_)); } }; struct sched_priority : concept<sched_priority> { int priority_; sched_priority(int p) : priority_(p) {} void apply(pthread_attr_t* a) const { sched_param p; p.sched_priority = priority_; THREAD_CHK_CALL(::pthread_attr_setschedparam(a, &p)); } }; class thread { private: pthread_t id_; unsigned joinable_ : 1; private: // noncopyable thread(thread const&); thread& operator=(thread const&); private: struct scoped_attr { pthread_attr_t a; scoped_attr() { THREAD_CHK_CALL(::pthread_attr_init(&a)); } ~scoped_attr() { ::pthread_attr_destroy(&a); } }; private: template<class functor> void start(functor const& f, pthread_attr_t const* a) { struct t // trampoline { static void* f(void* a) { // copy the functor and free the allocated memory before // executing the functor std::auto_ptr<functor> f(static_cast<functor*>(a)); functor e(*f); f.release(); return e(); } }; std::auto_ptr<functor> e(new functor(f)); THREAD_CHK_CALL(::pthread_create(&id_, a, &t::f, e.get())); e.release(); } void start(void*(*fun)(void*), void* arg, pthread_attr_t const* a) { THREAD_CHK_CALL(::pthread_create(&id_, a, fun, arg)); } public: thread() : id_(::pthread_self()), joinable_(1) {} thread(void*(*fun)(void*), void* arg) : joinable_(1) { this->start(fun, arg, 0); } template<class functor> thread(functor const& f) : joinable_(1) { this->start(f, 0); } template<class A> thread(void*(*fun)(void*), void* arg, concept<A> const& attr) { scoped_attr a; attr.self().apply(&a.a); int j; THREAD_CHK_CALL(::pthread_attr_getdetachstate(&a.a, &j)); joinable_ = PTHREAD_CREATE_JOINABLE == j; this->start(fun, arg, &a.a); } template<class functor, class A> thread(functor const& f, concept<A> const& attr) { scoped_attr a; attr.self().apply(&a.a); int j; THREAD_CHK_CALL(::pthread_attr_getdetachstate(&a.a, &j)); joinable_ = PTHREAD_CREATE_JOINABLE == j; this->start(f, &a.a); } ~thread() { if(joinable_) ::pthread_detach(id_); } void* join() { if(!joinable_) throw error("thread::join()", 0); void* p; THREAD_CHK_CALL(::pthread_join(id_, &p)); joinable_ = 0; return p; } }; void* f(void*) { return 0; } int main() { thread t(f, 0, detached | sched_policy(SCHED_FIFO) | sched_priority(1)); }

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Testing - further reading
by Andy Little 09 Apr '06

09 Apr '06

I came upon this report regarding "The Economic Impacts of Inadequate Infrastructure for Software Testing" published by NIST. It struck me that boosters might find it interesting in relation to testing. As well as info on tests It also provides information on the type of criteria users might employ to select software (Section 1.1 Software Quality Atrributes) with point by point atributes table (table 1.1) . I found it interesting to apply some of the questions in the table to my own work, which did well in some areas but not so well in others.. http://www.nist.gov/director/prog-ofc/report02-3.pdf regards Andy Little

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[review] promotion traits - review period extended until April 9.
by Tobias Schwinger 08 Apr '06

08 Apr '06

Dear users & members of Boost, I decided to extend the review period of the fast-track review for Promotion Traits until April 9 because there were only three reviews until now. That is, you have another three days to submit your evaluation of the proposed Boost software. Cheer up, it's a small & fast-to-track submission! We're very much looking forward to your reviews. Download URL ============ http://cpp-experiment.sourceforge.net/promote-20050917.tar.gz About the submission ==================== The Promotion Traits extend Boost.TypeTraits with templates that compute the type after promotion has been applied. Example: // given template<typename T> struct some_algorithm; template<> struct some_algorithm<int> { [...] }; // [...] more specializations // , [...] some_algorithm< typename integral_promotion<T>::type > [...] // makes some_algorithm work for any type T that promotes to an integer // (that is enums and smaller integral types) without the need for // additional specialization Review questions ================ Please always explicitly state in your review, whether you think the library should be accepted into Boost. You might want to comment on the following questions: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Regards, Tobias (Review Manager)

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[algorithm/string] Patch for BCB2006
by Nicola Musatti 08 Apr '06

08 Apr '06

Hallo, the enclosed patch brings support for the latest Borland compiler to the same level as bcc 5.6.4 . I tested it against bcc 5.8.2, bcc 5.6.4, VC++ 8.0 and g++ 3.4.2 . Cheers, Nicola Musatti ******Index: compare.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/algorithm/string/compare.hpp,v retrieving revision 1.6 diff -d -u -r1.6 compare.hpp --- compare.hpp 6 Mar 2006 18:05:10 -0000 1.6 +++ compare.hpp 8 Apr 2006 07:41:10 -0000 @@ -67,7 +67,7 @@ #if defined(__BORLANDC__) && (__BORLANDC__ >= 0x560) && (__BORLANDC__ <= 0x564) && !defined(_USE_OLD_RW_STL) return std::toupper(Arg1)==std::toupper(Arg2); #else - return std::toupper(Arg1,m_Loc)==std::toupper(Arg2,m_Loc); + return std::toupper<T1>(Arg1,m_Loc)==std::toupper<T2>(Arg2,m_Loc); #endif } @@ -120,7 +120,7 @@ #if defined(__BORLANDC__) && (__BORLANDC__ >= 0x560) && (__BORLANDC__ <= 0x564) && !defined(_USE_OLD_RW_STL) return std::toupper(Arg1)<std::toupper(Arg2); #else - return std::toupper(Arg1,m_Loc)<std::toupper(Arg2,m_Loc); + return std::toupper<T1>(Arg1,m_Loc)<std::toupper<T2>(Arg2,m_Loc); #endif } @@ -173,7 +173,7 @@ #if defined(__BORLANDC__) && (__BORLANDC__ >= 0x560) && (__BORLANDC__ <= 0x564) && !defined(_USE_OLD_RW_STL) return std::toupper(Arg1)<=std::toupper(Arg2); #else - return std::toupper(Arg1,m_Loc)<=std::toupper(Arg2,m_Loc); + return std::toupper<T1>(Arg1,m_Loc)<=std::toupper<T2>(Arg2,m_Loc); #endif } Index: detail/case_conv.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/algorithm/string/detail/case_conv.hpp,v retrieving revision 1.2 diff -d -u -r1.2 case_conv.hpp --- detail/case_conv.hpp 11 May 2005 09:17:14 -0000 1.2 +++ detail/case_conv.hpp 8 Apr 2006 07:35:10 -0000 @@ -33,7 +33,7 @@ #if defined(__BORLANDC__) && (__BORLANDC__ >= 0x560) && (__BORLANDC__ <= 0x564) && !defined(_USE_OLD_RW_STL) return std::tolower( Ch); #else - return std::tolower( Ch, m_Loc ); + return std::tolower<CharT>( Ch, m_Loc ); #endif } private: @@ -53,7 +53,7 @@ #if defined(__BORLANDC__) && (__BORLANDC__ >= 0x560) && (__BORLANDC__ <= 0x564) && !defined(_USE_OLD_RW_STL) return std::toupper( Ch); #else - return std::toupper( Ch, m_Loc ); + return std::toupper<CharT>( Ch, m_Loc ); #endif } private: Index: detail/classification.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/algorithm/string/detail/classification.hpp,v retrieving revision 1.7 diff -d -u -r1.7 classification.hpp --- detail/classification.hpp 11 May 2005 09:17:14 -0000 1.7 +++ detail/classification.hpp 7 Apr 2006 07:45:49 -0000 @@ -46,7 +46,7 @@ return std::use_facet< std::ctype<CharT> >(m_Locale).is( m_Type, Ch ); } - #if defined(__BORLANDC__) && (__BORLANDC__ >= 0x560) && (__BORLANDC__ <= 0x564) && !defined(_USE_OLD_RW_STL) + #if defined(__BORLANDC__) && (__BORLANDC__ >= 0x560) && (__BORLANDC__ <= 0x582) && !defined(_USE_OLD_RW_STL) template<> bool operator()( char const Ch ) const {

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Re: [boost] Sealed C++ class (why this inheritance is virtual)
by Martin Bonner 07 Apr '06

07 Apr '06

----Original Message---- From: Vladislav Lazarenko > I know that virtual inheritance may cause problems in > generally, but I see no possible problems with this code. You mean apart from a standard conforming compiler being required to reject the code? -- Martin Bonner Martin.Bonner(a)Pitechnology.com Pi Technology, Milton Hall, Ely Road, Milton, Cambridge, CB4 6WZ, ENGLAND Tel: +44 (0)1223 203894

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Sealed C++ class.
by Vladislav Lazarenko 07 Apr '06

07 Apr '06

Dear Boost community, I thank you for such wonderful library, I can not even imagine my life without Boost. Great work, team! I propose to add the small but sometimes very useful class (like boost::noncopyable) I developed it in hope it will be useful and included into the best C++ framework in the world. Note that I have tested this class only with: 1) Microsoft Visual C++ .NET 55537-640-4008961-18142 2) Microsoft Visual C++ .NET 69462-112-0617214-18401 But I think it won't be a problem to compile with gcc and so one. And, surely, sorry if there is already such class in the Boost, I did not found. If it is, please give me the link, I will take a look. Please review and let me know what you think by replying to this message. Thank you very much in advance. // // Copyright (c) 2006 Vladislav Lazarenko <snail(a)b2bits.com> // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) // #ifndef BOOST_SEALED_HPP #define BOOST_SEALED_HPP // MS compatible compilers support #pragma once. #if defined(_MSC_VER) && (_MSC_VER >= 1020) # pragma once #endif namespace boost { // protection from unintended ADL namespace sealed_ { template <typename T1, typename T2> class sealed_impl { friend typename T1; friend typename T2; private: sealed_impl() {} ~sealed_impl() {} }; } /*! The sealed classes is used to prevent derivation from a class. An error occurs if a sealed class is specified as the base class of another class. A sealed class cannot also be an abstract class. */ template <typename T> class sealed : virtual private sealed_::sealed_impl<sealed, T> { public: //! Constructor. sealed() {} //! Destructor. ~sealed() {} }; // Usage example: /* class UniquePerson : public boost::sealed<UniquePerson> { public: UniquePerson() {} ~UniquePerson() {} }; */ } #endif

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bug: cyclic header dependencies in type_traits
by Scott McPeak 06 Apr '06

06 Apr '06

In Boost 1.33.1, the following headers are involved in an #inclusion cycle: boost/type_traits/is_scalar.hpp boost/type_traits/is_enum.hpp boost/type_traits/is_convertible.hpp boost/type_traits/is_abstract.hpp boost/type_traits/is_class.hpp This causes a problem for standards-compliant compilers because, depending on where you enter the cycle, some template's declaration will not be seen before it is used. For example, entering at is_scalar.hpp (which happens when you include optional.hpp) causes the definition of is_class<> to be seen before the declaration of is_scalar<>, but the former uses the later. The problem was introduced in the change from 1.32 to 1.33, when is_abstract.hpp started being #included by is_convertible.hpp. For reasons I still don't fully understand, this doesn't always actually cause a problem. I think it has to do with the mysterious BOOST_NO_IS_ABSTRACT macro; my understanding of the intricacies of Boost configuration is very limited. The place I ran into this was using an EDG-based front end to parse the preprocessed output of Sun CC 5.7 on solaris-sparc; input is "#include <boost/optional.hpp>"; using Boost 1.33.0 or 1.33.1. I can't repro on linux or with gcc, nor with the latest CVS version of Boost. But regardless, the cycle is still present in the latest CVS, and cyclic header dependencies are usually a bug. -Scott

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Ann: Statistics/Special Functions/Numeric Methods Toolkit
by John Maddock 06 Apr '06

06 Apr '06

Gentlemen, This is to announce a new library added to the file vault, it is a work in progress and is intended to fulfil two needs: 1) To provide a small number of high quality special functions, initially these will be concentrated on functions used in statistical applications (with a strong nod towards Paul Bristow's existing work in this area). The functions currently implemented are the gamma/beta/erf functions along with the incomplete gamma and beta functions (four variants of each). All the implementations are fully generic and support the use of arbitrary "real-number" types, although they are optimised for use with types with known-about mantissa sizes: typically float, double or long double. Use of these functions with interval arithmetic (Boost.Interval) isn't quite supported yet, but it's something I want to investigate soon. 2) To provide at least some of the tools required to implement mathematical special functions, hopefully the presence of these will encourage other authors to contribute more special function implementations in the future. Currently implemented are helpers for the evaluation of infinite series, continued fractions and rational approximations. There are also classes for the manipulation of polynomials, for testing a special function against tabulated test data, and for the rapid generation of test data and/or data for output to an external graphing application. I've been keeping deliberately quiet about this for a while (with apologies to Paul Bristow), as I wanted to be certain that these special function implementations would offer something over and above what is available elsewhere. I still have some way to go here: erf and lgamma in particular still need work, but the incomplete gamma and beta functions already typically have 10 times lower error bounds than Cephes and GSL, and in one spectacular case 10^11 times more accurate (which is to say there is a domain of the incomplete gamma where Cephes and GSL have hardly any significant digits correct). Preliminary documentation is available here: http://www.johnmaddock.co.uk/toolkit and includes quite a lot of information already, including descriptions of implementation methodologies etc. There's also a roadmap of future work, open issues, and what needs to be done before a final release etc: http://www.johnmaddock.co.uk/toolkit/libs/math/doc/html/math_toolkit/status… The actual source code, is available for download in the vault: http://boost-consulting.com/vault/index.php?action=downloadfile&filename=ma… Regards, John Maddock.

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[Bug] Interaction between date_time and filesystem libraries
by Joe Gottman 06 Apr '06

06 Apr '06

When I try to the following code under VC6.0: #include <boost/date_time/gregorian/greg_date.hpp> #include <boost/filesystem/convenience.hpp> I get the following error: error C2955: 'equivalent' : use of class template requires template argument list : see declaration of 'equivalent' If I reverse the order of inclusion there is no error. Joe Gottman

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