The following code example is taken from the book
C++ Templates - The Complete Guide
by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002
© Copyright David Vandevoorde and Nicolai M. Josuttis 2002
template <typename FO1, typename FO2>
class Composer : private FO1, private FO2 {
public:
// constructor: initialize function objects
Composer(FO1 f1, FO2 f2)
: FO1(f1), FO2(f2) {
}
// ``function call'': nested call of function objects
double operator() (double v) {
return FO2::operator()(FO1::operator()(v));
}
};