-----Original Message----- From: boost-bounces@lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of John Maddock Sent: Wednesday, June 08, 2011 5:05 PM To: boost@lists.boost.org Subject: Re: [boost] MS VC10 std::numeric_limits<float>::max_digits10 iswrong for float
Assuming I am right, I think this means that we need yet another macro (Groans and Cries of Oh No, not another!)
because
BOOST_NO_NUMERIC_LIMITS_LOWEST
not defined is no longer an indicator that
max_digits10 is available (and its values correct).
So do we need
BOOST_NO_NUMERIC_LIMITS_MAX_DIGITS10
which should be defined by default, and only undefined for those libraries supporting C++0X std::numeric_limits with correct values like recent GCC - and others (but not <= VC10)?
Views?
Sigh.... I guess so. Care to submit a patch?
in dinkumware.hpp I think it should be // C++0x headers implemented in 520 (as shipped by Microsoft) (assuming 520 is the version shipped with VC10 and that VC11 will correct and bump _CPPLIB_VER ?) Note _CPPLIB_VER <= rather than < 520 for other similar macros #if !defined(_CPPLIB_VER) || _CPPLIB_VER <= 520 # define BOOST_NO_NUMERIC_LIMITS_ MAX_DIGITS10 #endif but there are many other compilers' config files and I'm not clear which versions implement C++0X and thus presumably max_digits10 - and if anyone else has had a mental aberration/fat finger? What I'm expecting people to be able to write is something like int max_digits10; #ifdef BOOST_NO_NUMERIC_LIMITS_ MAX_DIGITS10 max_digits10 = 2 + std::numeric_limits<FPT>::digits * 3010/10000; #else max_digits10 = std::numeric_limits<FPT>::max_digits10; #endif Paul --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow@hetp.u-net.com