Is it possible to move method definition outside declaration?
template <typename T1>
class A
{
template <bool T2>
class B;
template<>
class B<true>
{
void f() { /* Do smg */ }
}
class B<false>
{
void f() { /* Do smg else */ }
}
}
If I try to define f() outside class declaration, like this
template <typename T1>
template <>
void A<T1>::B<true>::f() { /* Do smg */ }
compiler gives error C3855: template parameter T2 is incompatible with the declaration.
You cannot explicitly specialize a class member template of a non-specialized class template, from [temp.expl.spec]:
In an explicit specialization declaration for a member of a class template or a member template that appears in namespace scope, the member template and some of its enclosing class templates may remain unspecialized, except that the declaration shall not explicitly specialize a class member template if its enclosing class templates are not explicitly specialized as well.
Even the explicit specialiation of B inside of the definition of A is ill-formed. If you need to do such a thing, I would simply not use a member class template for B.
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