printmax.cpp

C++ Templates 完全导引范例

/* The following code example is taken from the book
 * "C++ Templates - The Complete Guide"
 * by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002
 *
 * (C) Copyright David Vandevoorde and Nicolai M. Josuttis 2002.
 * Permission to copy, use, modify, sell and distribute this software
 * is granted provided this copyright notice appears in all copies.
 * This software is provided "as is" without express or implied
 * warranty, and with no claim as to its suitability for any purpose.
 */
#include <vector>
#include <list>
#include <algorithm>
#include <iostream>
#include "MyClass.hpp"

template <typename T>
void print_max (T const& coll)
{
    // declare local iterator of collection
    typename T::const_iterator pos;

    // compute position of maximum value
    pos = std::max_element(coll.begin(),coll.end());

    // print value of maximum element of coll (if any):
    if (pos != coll.end()) {
        std::cout << *pos << std::endl;
    }
    else {
        std::cout << "empty" << std::endl;
    }
}

int main()
{
    std::vector<MyClass> c1;
    std::list<MyClass>   c2;
    //...
    print_max (c1);
    print_max (c2);
}