Re: Where are std::sinf( float ) etc.

[Howard Hinnant <hhinnant at apple dot com>]

On Dec 29, 2005, at 1:52 PM, Gabriel Dos Reis wrote:

> Howard Hinnant <hhinnant@apple.com> writes:
>
> | We seem to have already merged (perhaps incompletely) some parts of
> | this very part of TR1 as if it was already standard.
>
> I'm confused as to what you're referring to: the C++0x working paper
> or the libstdc++ implementation?

Sorry for the ambiguous language.

I meant, assuming appropriate configure, that gcc 4 appears to have  
the following behavior:

#include <cmath>
#include <iostream>

int main()
{
    // gcc 4 compiles and executes the following line as if sin 
(1.0).  The C++03 standard
    // says it should be ambiguous.  TR1 says it should do what gcc  
4 does.
    std::cout << std::sin(1) << '\n';

    // gcc 4 finds the following line ambiguous, in agreement with C+ 
+03, but in disagreement
    // with TR1.  This is despite the fact that gcc 4 has gone to  
some effort to disambiguate
    // many other calls to atan2, in disagreement with C++03, but in  
agreement with TR1
    std::cout << std::atan2(1.0F, 1.0) << '\n';

    // gcc 4 compiles and executes the following line, in  
disagreement with C++03, but in
    // agreement with TR1.
    std::cout << std::signbit(1.0) << '\n';
}

Is there a clear policy for libstdc++ (gcc) for what parts of TR1 get  
adopted today as if they were already part of the standard?  Or is it  
handled on a case-by-case basis using engineering judgement?

-Howard