countof()’s full requirements

• And we know the following data types must be dealt with:

• • C style arrays
  • C style string (char const *)
  • MFC containers
  • STL containers and strings

• The countof() function can be called with a reference to any of the above types

• • Explicit specialization can only be done on exact types (doh!)
  • But, different overloads of the countof() signature can handle different kinds of containers