Question

Is there a way to have a 64 bit enum in C++? Whilst refactoring some code I came across bunch of #defines which would be better as an enum, but being greater than 32 bit causes the compiler to error.

For some reason I thought the following might work:

enum MY_ENUM : unsigned __int64   {       LARGE_VALUE = 0x1000000000000000,   }; 

Answer 1

I don’t think that’s possible with C++98. The underlying representation of enums is up to the compiler. In that case, you are better off using:

const __int64 LARGE_VALUE = 0x1000000000000000L; 

As of C++11, it is possible to use enum classes to specify the base type of the enum:

enum class MY_ENUM : unsigned __int64 {     LARGE_VALUE = 0x1000000000000000ULL }; 

In addition enum classes introduce a new name scope. So instead of referring to LARGE_VALUE, you would reference MY_ENUM::LARGE_VALUE.