The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference, 2nd Edition
by Nicolai M. Josuttis, Addison Wesley Longman, 2012
Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis
#include <list>
#include <algorithm>
#include <iostream>
#include "print.hpp"
using namespace std;
// function object that adds the value with which it is initialized
class AddValue {
private:
int theValue; // the value to add
public:
// constructor initializes the value to add
AddValue(int v) : theValue(v) {
}
// the "function call" for the element adds the value
void operator() (int& elem) const {
elem += theValue;
}
};
int main()
{
list<int> coll;
// insert elements from 1 to 9
for (int i=1; i<=9; ++i) {
coll.push_back(i);
}
PRINT_ELEMENTS(coll,"initialized: ");
// add value 10 to each element
for_each (coll.begin(), coll.end(), // range
AddValue(10)); // operation
PRINT_ELEMENTS(coll,"after adding 10: ");
// add value of first element to each element
for_each (coll.begin(), coll.end(), // range
AddValue(*coll.begin())); // operation
PRINT_ELEMENTS(coll,"after adding first element: ");
}