[boost] [config] Need a slightly different BOOST_STATIC_CONSTANT

From: Michael Marcin (mmarcin_at_[hidden])
Date: 2007-04-30 15:32:20

Hi,

I have a snippet of code that looks something like

template< std::size_t N >
class something
{
    static const std::size_t count = N;
};

On the RVCT 2.2 compiler this fails to compile with an internal error.
The obvious workaround, and the one chosen by BOOST_STATIC_CONSTANT is

template< std::size_t N >
class something
{
   enum { count = N };
};

This compiles but through probably another compiler bug during SFINAE 
overload resolution with a streaming operator called with a type of 
something it trys to instantiate say boost::is_pod< something<0>::(unamed) 
 >, fails and the compilation aborts.  The workaround for this is to name the 
enumeration.

template< std::size_t N >
class something
{
   enum stupid_name_for_rvct { count = N };
};

This works fine and I've been using it for a while.  However I'm now porting 
to MinGW GCC and I have SFINAE overloads which compare for instance 
something<0>::count to something<1>::count.  MinGW gives a slew of warnings 
and eventually aborts the compilation.  Using the static const std::size_t 
implementation of count it works fine.

Sorry for speaking about the problem in such an unclear way but at the 
moment I don't have a simple reproducable case.

This is basically the problem that BOOST_STATIC_CONSTANT was designed to 
solve IIUC but I need it to name my enumerations for me under RVCT.  Perhaps 
something could be done using a slightly decorated line number.  This would 
restrict you to one use of BOOST_STATIC_CONSTANT per line but that seems 
perfectly acceptable to me.

Thanks,

Michael Marcin