The following code example is taken from the book
C++ Templates - The Complete Guide, 2nd Edition
by David Vandevoorde, Nicolai M. Josuttis, and Douglas Gregor,
Addison-Wesley, 2017
© Copyright David Vandevoorde, Nicolai M. Josuttis, Douglas Gregor 2017
#include <vector>
#include <list>
template<typename T>
struct ElementT; // primary template
template<typename T>
struct ElementT<std::vector<T>> { // partial specialization for std::vector
using Type = T;
};
template<typename T>
struct ElementT<std::list<T>> { // partial specialization for std::list
using Type = T;
};
//...
template<typename T, std::size_t N>
struct ElementT<T[N]> { // partial specialization for arrays of known bounds
using Type = T;
};
template<typename T>
struct ElementT<T[]> { // partial specialization for arrays of unknown bounds
using Type = T;
};
//...