[Bug c++/66472] -Wshadow gets confused by using statements in template classes

["chtz at informatik dot uni-bremen.de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66472

--- Comment #6 from Christoph Hertzberg <chtz at informatik dot uni-bremen.de> ---
Ok, good point on shadowing free functions.
Next pathological example: If you have a template specialization of your Base
with a static member variable called `size`, wouldn't the warning make sense?

template <class T>
struct Base {
  Base(int y) {std::cout << "y=" <<y <<"\n";}
  T size();
};

template<class T>
struct Bar : Base<T> {
  using Base<T>::size;
  Bar(int size) : Base<T>(size) {}
  Bar() : Base<T>(size) {} // only works for T==int
};

// Specialization, probably not visible when Bar is defined:
template<>
struct Base<int> {
  Base<int>(int x) {std::cout << "x=" <<x <<"\n";}
  const static int size=42;
};