How do I get the fundamental type of an enum?

Question

With a declaration such as:

enum DrawBoldMode : unsigned
{
    DBM_NONE =              0,
    DBM_ITEM =              1<<0,   // bold just the nearest          


        

Answer 1

std::underlying_type is available in GCC 4.7, but until then you can get an approximate emulation with templates:

#include 
// This is a hack because GCC 4.6 does not support std::underlying_type yet.
// A specialization for each enum is preferred
namespace detail {
    template 
    struct filter;

    template 
    struct filter {
        typedef typename std::tuple_element<0, Acc>::type type;
    };

    template 
    struct filter, Head, Tail...>
    : std::conditional, Tail...>
                      , filter, Tail...>
                      >::type {};

    template 
    struct find_best_match : filter, In...> {};
}

namespace std {
    template 
    struct underlying_type : detail::find_best_match {};
}

It doesn't give you the exact type, but it gives you one with the same size and signedness characteristics.