Re: [v3] traits duplicate removal

[Paolo Carlini <pcarlini at suse dot de>]

Benjamin Kosnik wrote:

> This merges various duplicate traits code scattered around the library
> into ext/type_traits.h. In doing so, all duplicate effort has been
> eliminated, and essential traits missing from std::tr1's <type_traits>
> have been found.
>
> If we find new and useful traits, they should go in <ext/type_traits.h>.
>
> If people want to use type_traits in their own code, I suggest using 
>
> <tr1/type_traits>
>  
Benjamin, we have a problem with -pedantic:

#include <tr1/random>

int main()
{
 std::tr1::mt19937 mt;
}

paolo:~/Work/tr1_random/scratch> g++ -pedantic mt.cc
In file included from 
/home/paolo/Gcc/svn-dirs/trunk-install/lib/gcc/i686-pc-linux-gnu/4.2.0/../../../../include/c++/4.2.0/tr1/random:2569,
                from mt.cc:1:
/home/paolo/Gcc/svn-dirs/trunk-install/lib/gcc/i686-pc-linux-gnu/4.2.0/../../../../include/c++/4.2.0/ext/type_traits.h: 
In instantiation of '__gnu_cxx::__numeric_traits<double>':
/home/paolo/Gcc/svn-dirs/trunk-install/lib/gcc/i686-pc-linux-gnu/4.2.0/../../../../include/c++/4.2.0/tr1/random.tcc:731:   
instantiated from here
/home/paolo/Gcc/svn-dirs/trunk-install/lib/gcc/i686-pc-linux-gnu/4.2.0/../../../../include/c++/4.2.0/ext/type_traits.h:134: 
error: ISO C++ forbids initialization of member constant 
'__gnu_cxx::__numeric_traits<double>::__min' of non-integral type 'const 
double'
/home/paolo/Gcc/svn-dirs/trunk-install/lib/gcc/i686-pc-linux-gnu/4.2.0/../../../../include/c++/4.2.0/ext/type_traits.h:135: 
error: ISO C++ forbids initialization of member constant 
'__gnu_cxx::__numeric_traits<double>::__max' of non-integral type 'const 
double'

Note that the warning is *not* suppressed by the pragma system headers, 
I'm afraid we have to factor out the numeric_traits class...

Paolo.