modern-cpp-tutorial/code/2/2.14.default.template.param.cpp

//
// 2.4.default.template.param.cpp
// chapter 2 language usability
// modern cpp tutorial
//
// created by changkun at changkun.de
// https://github.com/changkun/modern-cpp-tutorial
//

#include <iostream>

template<typename T = int, typename U = int>
auto add(T x, U y) -> decltype(x+y) {
    return x+y;
}

int main() {
    std::cout << add(1, 2) << std::endl;
}