use of vector<int>::value_type?

[Speedo]

value_type and similar typedefs are useful for writing generic code that can work with any STL container. Eg:

#include <vector>
#include <list>
#include <iostream>

template<typename Container>
class Foo
{
  Container m_con;

public:
  Foo(const Container& c) : m_con(c) { }

  typename Container::value_type
    GetFirst( ) { return *(m_con.begin( )); }
};

int main( )
{
  std::vector<int> a;
  a.push_back(20);

  std::list<float> b;
  b.push_back(1.234f);

  Foo<std::vector<int> > c(a);
  Foo<std::list<float> > d(b);

  std::cout << c.GetFirst( ) << std::endl;
  std::cout << d.GetFirst( ) << std::endl;
  
  return 0;
}