// test1_template.cc    basic test of templates

#include <iostream>
#include <string>              // this is definately NOT <string.h> !!
using namespace std;

template <class T> class foo;  // a declaration that foo is a template class

template <class T>             // declaration or specification of foo
class foo                      // the user gets to choose a type for 'T'
{
  public:
    foo();
    void put(T value);
    T get(int &j);
  private:
    int mine(T &a_value);
    T   a;
    int i;
};                             // remember the ending semicolon

template <class T>             // implementation or body of foo
foo<T>::foo()
{
  i = 1;
  // can not initialize 'a' here because we do not know what type 'T' is
}

template <class T>
void foo<T>:: put(T value)
{
  a = value;  // since 'a' and 'value' are both type 'T' this is OK
}

template <class T>
T foo<T>::get(int &j)
{
  j = ++i;   // 'j' was passed by reference and gets incremented 'i'
  return a;  // return 'a' whatever type it is
}

int main(int argc, char *argv[])
{
  foo<double> x; // in object 'x', the type 'T' is double
  double y;
  int j;

  x.put(1.5);    // put the value 1.5 into 'a' in 'x'
  y = x.get(j);  // increment 'i' in 'x' and return 'a'

  cout << "j= " << j << "  y= " << y << endl;

  foo<string> glob; // in object 'glob' , the type 'T' is string::string
  string y_string;

  glob.put("abc");  // put the string "abc" int 'a' in 'glob'
  y_string = glob.get(j); // increment 'i' in 'glob' and return 'a'

  cout << "j= " << j << "  y_string= " << y_string << endl;
  return 0;
}