Enum with 64 bit underlying integer

Question

I'm using gcc, which implements enums as 32 bit integers on the architecture I have (don't know in general). If I try to assign an enum value too large, I get

warning: integer overflow in expression

Is there a way to make gcc use 64 bit integers as the underlying integer type? A gcc specific way is fine, although if there's a portable way, that's even better.

** Edit ** This is a related post: http://stackoverflow.com/questions/76624/64-bit-enum-in-c

Unlike that question, I'm also interested in gnu extensions.

Answer 1

one option: create a template class with a static const member of a specific type.

for example std::tr1::integral_constant, declared in c++/tr1/type_traits in the GNU distribution (at least, the one i'm using).

for an enum value: your declaration could matter (e.g., use U, L as appropriate)

Answer 2

The following works for me with -std=c++0x, but not with -std=c++98 though

enum EnumFoo {
    FooSomething = 0x123456789ULL
};

I tested this with

$ g++ --version
g++ (Ubuntu 4.4.3-4ubuntu5) 4.4.3