You can use partial specialization. No need of std::enable_if
.
//primary template
template<int a, int b>
class foo
{
//whatever
};
//partial specialization
template<int b>
class foo<5,b> //when a = 5, this specialization will be used!
{
int c; //it has member c
};
Usage:
foo<1,3> f1; //primary template is used
foo<5,3> f2; //partial specialization is used