Re: [boost] Is there a macro to test ifstd::numerc_limits<>::max_digits10 is supported by a platform?

Subject: Re: [boost] Is there a macro to test ifstd::numerc_limits<>::max_digits10 is supported by a platform?
From: John Maddock (boost.regex_at_[hidden])
Date: 2012-06-14 07:13:43

>A proposed (but not reverted) fix for
>
> Trac #5758: Boost.Test Floating-point comparison diagnostic output does 
> not support radix 10
>
>        if( std::numeric_limits<T>::is_specialized && 
> std::numeric_limits<T>::radix == 10 )
>            ostr.precision( 2 + std::numeric_limits<T>::max_digits10);
>            // Assume that max_digits10 is provided for all radix 10 as 
> they are quite new,
>            // and anyway Kahan formula will not work for decimal.
>
> has caused trouble on platforms that do not yet support
>
> std::numeric_limits<T>::max_digits10
>
> We need a macro perhaps BOOST_NO_NUMERIC_LIMITS_ MAX_DIGITS10
>
> that will prevent the compiler seeing this code if max_digits10 is not 
> supported.

Try BOOST_NO_NUMERIC_LIMITS_LOWEST as a proxy?

John.