Re: [boost] [1.53.0] Beta release candidates 2 now available for testing

Subject: Re: [boost] [1.53.0] Beta release candidates 2 now available for testing
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2013-01-05 17:45:46

Le 05/01/13 18:37, Marshall Clow a écrit :
> On Jan 4, 2013, at 11:25 AM, Marshall Clow <mclow.lists_at_[hidden]> wrote:
>
>> Updated release candidate files for 1.53.0 beta 1 are available at
>> http://boost.cowic.de/rc/
>>
>> As always, the release managers would appreciate it if you download
>> the candidate of your choice and give building it a try. Please report
>> both success and failure, and anything else that is noteworthy.
> I built the RC on Mac OS X with both clang and gcc w/o errors.
> However, when I built using clang and libc++ in C++11 mode, I found two problems:
>
> 	./b2 toolset=clang  cxxflags="-std=c++11 -stdlib=libc++ -Wno-unused-variable" linkflags="-stdlib=libc++"
>
> Issue #1:
>
>> clang-darwin.compile.c++ bin.v2/libs/chrono/build/clang-darwin-11/release/threading-multi/chrono.o
>> In file included from libs/chrono/src/chrono.cpp:14:
>> In file included from ./boost/chrono/detail/inlined/chrono.hpp:13:
>> In file included from ./boost/chrono/chrono.hpp:11:
>> ./boost/chrono/duration.hpp:353:49: error: constexpr function never produces a constant expression
>>          static BOOST_CHRONO_LIB_CONSTEXPR float lowest() BOOST_CHRONO_LIB_NOEXCEPT_OR_THROW
>>                                                  ^
>> ./boost/chrono/duration.hpp:355:21: note: non-constexpr function 'max' cannot be used in a constant expression
>>              return -(std::numeric_limits<float>::max) ();
>>                      ^
>> /usr/bin/../lib/c++/v1/limits:443:43: note: declared here
>>      _LIBCPP_INLINE_VISIBILITY static type max() _NOEXCEPT {return __base::max();}
>>                                            ^
> This is a bug in libc++; std::numeric_limits<>::max() is not marked as constexpr.
> This has been fixed in the libc++ trunk, and should appear in the next clang/libc++ release.
Hi, I defined BOOST_CHRONO_LIB_CONSTEXPR as follows to avoid this problem.

#if defined( BOOST_NO_CXX11_NUMERIC_LIMITS )
#define BOOST_CHRONO_LIB_CONSTEXPR
#else
#define BOOST_CHRONO_LIB_CONSTEXPR BOOST_CONSTEXPR
#endif

Shouldn't BOOST_NO_CXX11_NUMERIC_LIMITS be defined as it doesn't 
providesa C++11 implementation, or should Boost.Chrono take in account 
the missing feature of libc++ individually?

BTW, which version of libc++ are you using?

Best,
Vicente