how template works in c++ code example

Example 1: cpp how to create an object of template class

template class  Graph<string>;

Example 2: templates of templates c++

namespace std {
  template<typename t> struct hash<MyClass<t>>
  {
  	size_t operator() (const MyClass<t>& c) const;
  }
}

// You can also do things like

template<template<typename t> class type> func_name<type<t>>();