[boost] Re: Proposal: rational numbers class

From: Ed Brey (brey_at_[hidden])
Date: 1999-12-06 09:44:12

"Moore, Paul" wrote:
> 
> One annoyance (and the reason I ditched the as<> approach) is that MS Visual
> C++ doesn't like the construct much. (OK, so nobody is surprised - but sadly
> I use MSVC). The issue is that
> 
>     using boost::rational_cast;
>     cout << rational_cast<float>(r);
> 
> complains about
> 
> rational_test.cpp(25) : error C2679: binary '<<' : no operator defined which
> takes a right-hand operand of type '' (or there is no acceptable conversion)
> rational_test.cpp(25) : error C2062: type 'float' unexpected
> 
> whereas
> 
>     cout << boost::rational_cast<float>(r);
> 
> works fine.
> 
> Does anyone know any magic incantations which would persuade MSVC to accept
> this (excluding the obvious one of "go to another compiler vendor")?

This is a case where it is ligitimate to (hopefully temporarily)
employ the evils of a macro to make up for the evils of Microsoft.

#include <boost/rational.hpp>

#if !defined(_MSC_VER) || _MSC_VER > 1200 || defined(__ICL)
        using boost::rational_cast;
#else
        #define rational_cast boost::rational_cast
#endif