functors/compose1.cpp

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


#include <iostream>
#include "math1.hpp"
#include "compose1.hpp"

template<typename FO>
void print_values (FO fo) 
{
    for (int i=-2; i<3; ++i) {
        std::cout << "f(" << i*0.1
                  << ") = " << fo(i*0.1)
                  << "\n";
    }
}

int main()
{
    // print sin(abs(-0.5))
    std::cout << Composer<Abs,Sine>(Abs(),Sine())(-0.5) << "\n\n";

    // print abs() of some values
    print_values(Abs());
    std::cout << '\n';

    // print sin() of some values
    print_values(Sine());
    std::cout << '\n';

    // print sin(abs()) of some values
    print_values(Composer<Abs, Sine>(Abs(), Sine()));
    std::cout << '\n';

    // print abs(sin()) of some values
    print_values(Composer<Sine, Abs>(Sine(), Abs()));
}