| // -*- C++ -*- |
| //===----------------------------------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is dual licensed under the MIT and the University of Illinois Open |
| // Source Licenses. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++98, c++03, c++11 |
| |
| #include <experimental/coroutine> |
| #include <vector> |
| #include <cassert> |
| |
| using namespace std::experimental; |
| |
| // This file tests, one shot, movable std::function like thing using coroutine |
| // for compile-time type erasure and unerasure. |
| |
| template <typename R> struct func { |
| struct promise_type { |
| R result; |
| func get_return_object() { return {this}; } |
| suspend_always initial_suspend() { return {}; } |
| suspend_always final_suspend() { return {}; } |
| void return_value(R v) { result = v; } |
| void unhandled_exception() {} |
| }; |
| |
| R operator()() { |
| h.resume(); |
| R result = h.promise().result; |
| h.destroy(); |
| h = nullptr; |
| 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) { co_return 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; |
| }; |
| |
| std::vector<int> yielded_values = {}; |
| int yield(int x) { yielded_values.push_back(x); return x + 1; } |
| float fyield(int x) { yielded_values.push_back(x); return static_cast<float>(x + 2); } |
| |
| void Do1(func<int> f) { yield(f()); } |
| void Do2(func<double> f) { yield(static_cast<int>(f())); } |
| |
| int main() { |
| Do1([] { return yield(43); }); |
| assert((yielded_values == std::vector<int>{43, 44})); |
| |
| yielded_values = {}; |
| Do2([] { return fyield(44); }); |
| assert((yielded_values == std::vector<int>{44, 46})); |
| } |