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

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

Howard Hinnant <hhinnant@apple.com> writes:

| On Dec 29, 2005, at 4:07 PM, Gabriel Dos Reis wrote:
| 
| > Howard Hinnant <hhinnant@apple.com> writes:
| >
| > [...]
| >
| > | > As to overloads for std::cosf (note the suffix), I find the
| > | > justificaton for them as "C99 compatibility" as dubious.
| > |
| > | Interesting.
| >
| > cos() is "overloaded" in C99 through <tgmath.h>; not cosf.  If the
| > motivation for a C++ library to add overloads for cosf is
| > compatibility then the motivation better finds a different, more
| > convincing, excuse.
| >
| > -- Gaby
| 
| My mistake again.  I thought Ed was simply asking for:
| 
|   float std::cosf( float );
| 
| which is required by C99.

No C++ standard requires that signature (for C99 compatibility.)

What libstdc++ does is to try to mess minimally with your "C" headers
<xxx.h>, so that if you include <math.h> chances are that your cosf() will
just work fine.  There is no std::cosf() because no such thing is
mandated. 
If I remember correctly (and my memory may be failing here), there is
a proposal to acknowledge that implementations could have <cxxx>  put
everything in both global and std:: scope.

When the C99 compat problem was urgent, we tried several variations,
and at some point we put them in __gnu_cxx.  The c_shawdow was an
effort to implement the standard letter, it never succeeded, partly
because for implementations like GCC, it was an unrealistic
requirement. 

|  Having that signature (not any overloads
| of it) in the name of "C99 compatibility" does not seem dubious to
| me.

Well, given that C99 does not have std::, the compatibility claim needs
more explanation.  If compability is a real issue, then the standard
should require that "C" headers are left *alone*, untouched.  But the
standard did something else, causing more troubles, and now we need
more kludge in the name of compatibility?

| I'm not sure where we started discussing overloading cosf, nor
| with what signature.

-- Gaby