Why is partial specialziation of a nested class template allowed, while complete isn't?
- by drhirsch
template<int x> struct A {
template<int y> struct B {};.
template<int y, int unused> struct C {};
};
template<int x> template<>
struct A<x>::B<x> {}; // error: enclosing class templates are not explicitly specialized
template<int x> template<int unused>
struct A<x>::C<x, unused> {}; // ok
So why is the explicit specialization of a inner, nested class (or function) not allowed, if the outer class isn't specialiced too? Strange enough, I can work around this behaviour if I only partially specialize the inner class with simply adding a dummy template parameter. Makes things uglier and more complex, but it works.
Note: I need this feature for recursive templates of the inner class for a set of the outer class.
To make things even more complicate, in reality I only need a template function instead of the inner class. But partial specialization of functions is generally disallowed somewhere else in the standard ^^
