promises.hpp

#pragma once
#include <coroutine>
 
namespace NNet {
 
struct TVoidPromise;
 
struct TVoidTask : std::coroutine_handle<TVoidPromise>
{
    using promise_type = TVoidPromise;
};
 
struct TVoidPromise
{
    TVoidTask get_return_object() { return { TVoidTask::from_promise(*this) }; }
    std::suspend_never initial_suspend() { return {}; }
    std::suspend_never final_suspend() noexcept { return {}; }
    void return_void() {}
    void unhandled_exception() {}
};
 
struct TVoidSuspendedPromise;
 
struct TVoidSuspendedTask : std::coroutine_handle<TVoidSuspendedPromise>
{
    using promise_type = TVoidSuspendedPromise;
};
 
struct TVoidSuspendedPromise
{
    TVoidSuspendedTask get_return_object() { return { TVoidSuspendedTask::from_promise(*this) }; }
    std::suspend_never initial_suspend() { return {}; }
    std::suspend_always final_suspend() noexcept { return {}; }
    void return_void() {}
    void unhandled_exception() {}
};
 
struct Self {
    bool await_ready() {
        return false;
    }
 
    bool await_suspend(std::coroutine_handle<> h) {
        H = h;
        return false;
    }
 
    auto await_resume() noexcept {
        return H;
    }
 
    std::coroutine_handle<> H;
};
} // namespace NNet