[boost] Re: min, max, GCC 2.95.3, and STLport

From: Eric Niebler (eric_at_[hidden])
Date: 2004-07-01 01:56:39

Martin Wille wrote:
> 
> 
> STLPort implements std::min in the namespace _STL.
> BOOST_USING_STD_MIN() correctly expands to: using _STL   ::min
> 
> The (shortened) result of preprocessing is:
> 
> namespace _STL  {
> 
> template <class _Tp>
> inline const _Tp& (min)(const _Tp& __a, const _Tp& __b) { return __b < 
> __a ? __b : __a; }
> template <class _Tp>
> inline const _Tp& (max)(const _Tp& __a, const _Tp& __b) {  return  __a < 
> __b ? __b : __a; }
> 
> template <class _Tp, class _Compare>
> inline const _Tp& (min)(const _Tp& __a, const _Tp& __b, _Compare __comp) {
>   return __comp(__b, __a) ? __b : __a;
> }
> 
> template <class _Tp, class _Compare>
> inline const _Tp& (max)(const _Tp& __a, const _Tp& __b, _Compare __comp) {
>   return __comp(__a, __b) ? __b : __a;
> }
> 
> }
> 
> (the complete preprocessed source can be found at: 
> http://tinyurl.com/yrflf )
> 
> I must be blind, I can't spot the line that hoists the contents of
> _STL:: into std::.
>

It's not there. STLPort must be #defining std to _STL.

> 
>> In the worst case, I suppose for this compiler/library combination we 
>> can import std::min/max into the boost namespace with a using 
>> declaration and make BOOST_USING_STD_MIN() expand to nothing. Martyn, 
>> can you try that and see if it works?
> 
> 
> Changing the source to
> 
> namespace notboost
> {
>     BOOST_USING_STD_MIN(); // moved to namespace scope
>     template <typename T>
>     T const &
>     proxy_min(T const &p, T const &q)
>     {
>          return min BOOST_PREVENT_MACRO_SUBSTITUTION(p, q);
>     }
> }
> 
> indeed makes gcc-2.95.3 accept the code.
> 

Well then, I guess that's what I'll do, unless somebody has a better 
idea. I'll sleep on it first.

Thanks again, Martin.

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com