| // -*- C++ -*- |
| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++98, c++03, c++11 |
| |
| #include <experimental/coroutine> |
| #include <cassert> |
| |
| #include "test_macros.h" |
| |
| using namespace std::experimental; |
| |
| // This file tests, multishot, movable std::function like thing using coroutine |
| // for compile-time type erasure and unerasure. |
| template <typename R> struct func { |
| struct Input {R a, b;}; |
| |
| struct promise_type { |
| Input* I; |
| R result; |
| func get_return_object() { return {this}; } |
| suspend_always initial_suspend() { return {}; } |
| suspend_never final_suspend() { return {}; } |
| void return_void() {} |
| template <typename F> |
| suspend_always yield_value(F&& f) { |
| result = f(I->a, I->b); |
| return {}; |
| } |
| void unhandled_exception() {} |
| }; |
| |
| R operator()(Input I) { |
| h.promise().I = &I; |
| h.resume(); |
| R result = h.promise().result; |
| return result; |
| }; |
| |
| func() {} |
| func(func &&rhs) : h(rhs.h) { rhs.h = nullptr; } |
| func(func const &) = delete; |
| |
| func &operator=(func &&rhs) { |
| if (this != &rhs) { |
| if (h) |
| h.destroy(); |
| h = rhs.h; |
| rhs.h = nullptr; |
| } |
| return *this; |
| } |
| |
| template <typename F> static func Create(F f) { |
| for (;;) { |
| co_yield f; |
| } |
| } |
| |
| template <typename F> func(F f) : func(Create(f)) {} |
| |
| ~func() { |
| if (h) |
| h.destroy(); |
| } |
| |
| private: |
| func(promise_type *promise) |
| : h(coroutine_handle<promise_type>::from_promise(*promise)) {} |
| coroutine_handle<promise_type> h; |
| }; |
| |
| int Do(int acc, int n, func<int> f) { |
| for (int i = 0; i < n; ++i) |
| acc = f({acc, i}); |
| return acc; |
| } |
| |
| int main(int, char**) { |
| int result = Do(1, 10, [](int a, int b) {return a + b;}); |
| assert(result == 46); |
| |
| return 0; |
| } |