/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* 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 <iostream>
#include <list>
#include <algorithm>
using namespace std;
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/
template <class T>
inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="")
{
typename T::const_iterator pos;
std::cout << optcstr;
for (pos=coll.begin(); pos!=coll.end(); ++pos) {
std::cout << *pos << ' ';
}
std::cout << std::endl;
}
// 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 of first element to each element
for_each (coll.begin(), coll.end(), // range
AddValue(*coll.begin())); // operation
PRINT_ELEMENTS(coll,"after adding first element: ");
}
/*
initialized: 1 2 3 4 5 6 7 8 9
after adding first element: 2 3 4 5 6 7 8 9 10
*/
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