Functional Composition in C++ ver. 1

gistfile1.cpp

#include<iostream>
#include<functional>
#include<cmath>

using namespace std;
using namespace std::tr1;

template<typename Param, typename Middle, typename Result>
function<Result(Param)> compose(const function<Result(Middle)>& f, const function<Middle(Param)>& g) {
    return [f, g](Param x){return f(g(x));};
}

int main(void) {
    function<double(double)> f = [](double x){return exp(x);};
    function<double(double)> g = [](double x){return pow(x, 2);};
    function<double(double)> h = [](double x){return -x + 1;};
    function<double(double)> composed = compose(compose(f, g), h);
    cout << composed(3) << endl;
}