// d2mcpp: https://github.com/mcpp-community/d2mcpp

// license: Apache-2.0

// file: src/cpp11/tests/00-auto-and-decltype/3.cpp

//

// Exercise/练习: cpp11 | 00 - auto and decltype | 函数返回值类型推导

//

// Tips/提示: 用后置返回 auto ... -> decltype(a - b) 让模板函数自动推导返回类型

//

// Docs/文档:

// - https://en.cppreference.com/w/cpp/language/auto

// - https://en.cppreference.com/w/cpp/language/decltype

// - https://github.com/mcpp-community/d2mcpp/blob/main/book/src/cpp11/00-auto-and-decltype.md

//

// 练习交流讨论: http://forum.d2learn.org/post/357

//

// Auto-Checker/自动检测命令:

//

// d2x checker auto-and-decltype-3

//

import std;

import d2x;

// 3. 函数返回值类型

auto add_func(int a, double b) -> decltype(a + b) {

return a + b;

}

template<typename T1, typename T2>

D2X_YOUR_ANSWER minus_func(T1 a, T2 b) -> D2X_YOUR_ANSWER {

return a - b;

}

int main() {

d2x::check_eq(minus_func(1, 2), -1, "minus_func(1, 2) == -1");

d2x::check_eq(minus_func(2, 1), 1, "minus_func(2, 1) == 1");

d2x::check_eq(minus_func(1, 2.1), -1.1, "minus_func(1, 2.1) == -1.1");

d2x::wait();

return 0;

}