Re: [boost] BOOST_ENUM proposal

From: Thorsten Ottosen (tottosen_at_[hidden])
Date: 2005-12-08 09:55:20

Frank Laub wrote:
> There should be no problems using this macro in a header file. I get around
> the one definition rule by simply making the enum actually be a namespace
> with static functions inside that namespace. So basically:
> 
> BOOST_ENUM(Foo, (a)(b))
> 
> expands into:
> 
> namespace Foo
> {
>     enum type
>     {
>         a,
>         b,
>         size = 2,
>         Invalid = -1
>     };
> 
>     typedef boost::array<const std::string, size+1> array_type;

Is it not possible to go for

typedef boost::array<const char*, size+1> array_type

?

>     static const array_type names =
>     {
>         "a",
>         "b",
>         "2"
>     };
> 
>     static const std::string& str(type index)
>     {
>         assert(index >= 0 && index <= size);
>         return names[(int)index];
>     }

and maybe a CT version:

template< type index >
inline const char* str()
{
   BOOST_STATIC_ASSERT( index > Invalid );
   return names[(int)index];
}

-Thorsten