execution_coro_example.cpp

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#if __cpp_impl_coroutine >= 201902L
#include <coroutine>
#include <forge/task.hpp>
#include <iostream>
using exec_env = std::execution::empty_env;
struct demo { struct promise_type : std::execution::with_awaitable_senders<promise_type> { demo get_return_object() { return {}; } std::suspend_never initial_suspend() noexcept { return {}; } std::suspend_never final_suspend() noexcept { return {}; } void return_void() {} void unhandled_exception() { std::terminate(); } }; };
demo run() { auto [v] = co_await (std::execution::just(20) | std::execution::then([](int x) { return x + 22; })); std::cout << "execution coro value: " << v << '\n'; }
int main() { run(); return 0; }
#else
#include <execution>
#include <iostream>
int main() { std::cout << "C++20 coroutines required\n"; (void)sizeof(std::execution::empty_env); return 0; }
#endif