specialize a member template without specializing its parent

Question

I have a class template nested inside another template. Partially specializing it is easy: I just declare another template< … > block inside its parent.

Answer 1

I tend not to use nested classes too much. My main complaint is that they have a tendency to bloat the code of the class they are nested in.

I would therefore propose another workaround:

namespace detail
{
  template  class BImpl;
  template  class BImpl > {};
  template  class BImpl {};
}

template 
class A
{
  template  struct B: BImpl {};
};

Just note that it requires to pass X as an argument to BImpl if ever you wish to also specialize A. Funny thing is that in this case, I end up with only partial specialization!