Question

When comparing enums that come from different sources such as those of the following code GCC emits warnings. Is there a way to avoid these warnings without c-style casts?

struct Enumerator {     enum { VALUE = 5 }; };  template<int V> struct TemplatedEnumerator {     enum { VALUE = V }; };  if(Enumerator::VALUE == TemplatedEnumerator<5>::VALUE) {   ... } 

And GCC emits the following type of warning:

GCC: warning: comparison between 'enum ...' and 'enum ...' 

Answer 1

Simple answer in your case: don’t use an enum, use an inline-defined static const int:

struct Enumerator {     static int const VALUE = 5; };  template<int V> struct TemplatedEnumerator {     static int const VALUE = V; }; 

In this special case, that’s equivalent and all compilers of the last few years should treat it so (I know for a fact that all the major ones do).

See also: static const Member Value vs. Member enum : Which Method is Better & Why?