[v3] Use Solaris prototypes if possible (PR libstdc++-v3/1773)

[Paolo Carlini]

On 08/18/2011 01:37 PM, Marc Glisse wrote:
> On Thu, 18 Aug 2011, Paolo Carlini wrote:
>
>> Indeed. I would say let's not re-order for now, I'll have a further 
>> look later on.
>
> Is that a "ok" for Rainer or just part of the discussion?
Sure. Actually the libstdc++ proper bits always were, I consider those 
more or less straightforward.
> namespace std {
>         void f();
> }
> using std::f;
> namespace std {
>         struct Complex{};
>         void f(Complex){}
> }
> //using std::f;
> namespace std {
>         using ::f;
>         namespace tr1 {
>                 using ::f;
>                 void f(std::Complex);
>         }
> }
>
> The compiler doesn't complain for this. It does if I change which 
> using is commented out [namespace.udecl]p11 in C++11. I just learned 
> this rule and haven't thought about the consequences yet. It looks 
> like as long as math.h is included before complex (and complex 
> includes cmath so that's the case), the std::fabs(std::complex) 
> overload is not imported in the global namespace and hence not in tr1 
> either. On the other hand, it means that the overloads in cmath for 
> cos/sin/etc taking an integral type are not imported in the global 
> namespace (so std::cos(0) works but cos(0) is ambiguous). Well, it 
> seems ok for now...
Thus, if I understand correctly your analysis (sorry I'm in the middle 
of something else) are we already ok? Is there something simple we 
can/should do right now to improve things (on Solaris and/or Linux)?

Thanks,
Paolo.