The following code example is taken from the book
Object-Oriented Programming in C++
by Nicolai M. Josuttis, Wiley, 2002
© Copyright Nicolai M. Josuttis 2002
// function object that adds the passed value
class Add {
private:
int val; // value to add
public:
// constructor (initializes the value to add)
Add(int w) : val(w) {
}
// `function call' (adds the value)
int operator() (int elem) const
{
return elem + val;
}
};