// bind example from http://www.cplusplus.com/reference/functional/bind/
//
// It can certainly be argued that lambda-functions are nearly
// a replacement for bind, but ofttimes bind expresses intention better,
// and is shorter.

#include <iostream>     // cout
#include <functional>   // bind

double divide(double x, double y) {
    return x/y;
}

using namespace std;
using namespace std::placeholders;		   // adds _1, _2, _3, …

int main () {

    cout << "10÷3 = " << divide(10, 3) << '\n';

    auto five = bind(divide, 10, 2);               // returns 10/2
    cout << "10÷2 = " << five() << '\n';           // 5

    auto half = bind(divide, _1, 2);               // returns x/2
    cout << "12.4÷2 = " << half(12.4) << '\n';     // 6.2

    auto revdiv = bind(divide, _2, _1);            // returns y/x
    cout << "5÷4 = " << revdiv(4,5) << '\n';       // 5/4 = 1¼

    auto invert = bind(divide, 1.0, _1);           // returns 1/x
    cout << "1÷3 = " << invert(3.0) << '\n';       // ⅓

    // Or, just use a lambda-function:
    auto invert2 = [](double d) {return divide(1.0, d);}; // returns 1/x
    cout << "1÷3 = " << invert2(3.0) << '\n';       // ⅓
}