PATCH: Apply Nathan's macro trick

[Nathan Myers]

On Thu, Apr 17, 2003 at 05:03:23AM -0500, Loren James Rittle wrote:
> This is the final form of <cmath> for the time being (related to
> dynamic visible) and the binding form I will use in <cstdio>,
> <cstdlib>, <cwchar>.   ...
> 
> 	* include/c_std/std_cmath.h (__gnu_cxx::__c99_binding): Rework
> 	to use Nathan's macro trick.
> 	(C99 FP capture): Only undefine, if captured.
> ... 
> + #define _GLIBCXX_C99_USING_0(__b, __c) __c
> + #define _GLIBCXX_C99_USING_1(__b, __c) __b
> + #define _GLIBCXX_C99_USING(__a,__b,__c) _GLIBCXX_C99_USING_ ## __a(__b, __c)
> + #define _GLIBCXX_C99_BIND(__a,__b) _GLIBCXX_C99_USING(__a, using ::__b;, )

This re-expression of my posting is so elegant, I wonder if the 
names are still appropriate.  Maybe the first three names should be
_GLIBCXX_IF_0, _GLIBCXX_IF_1, and _GLIBCXX_IF, and should appear in
a more generic header.

Nathan Myers
ncm-nospam