clang/test/AST/Inputs/std-coroutine.h

   1 // RUN: %clang_cc1 -triple x86_64-apple-darwin9 %s -std=c++20 -fcoroutines-ts -fsyntax-only -Wignored-qualifiers -Wno-error=return-type -verify -fblocks -Wno-unreachable-code -Wno-unused-value
   2 #ifndef STD_COROUTINE_H
   3 #define STD_COROUTINE_H
   4
   5 namespace std {
   6
   7 template <typename R, typename...> struct coroutine_traits {
   8   using promise_type = typename R::promise_type;
   9 };
  10
  11 template <typename Promise = void> struct coroutine_handle;
  12
  13 template <> struct coroutine_handle<void> {
  14   static coroutine_handle from_address(void *addr) noexcept {
  15     coroutine_handle me;
  16     me.ptr = addr;
  17     return me;
  18   }
  19   void operator()() { resume(); }
  20   void *address() const noexcept { return ptr; }
  21   void resume() const { __builtin_coro_resume(ptr); }
  22   void destroy() const { __builtin_coro_destroy(ptr); }
  23   bool done() const { return __builtin_coro_done(ptr); }
  24   coroutine_handle &operator=(decltype(nullptr)) {
  25     ptr = nullptr;
  26     return *this;
  27   }
  28   coroutine_handle(decltype(nullptr)) : ptr(nullptr) {}
  29   coroutine_handle() : ptr(nullptr) {}
  30   //  void reset() { ptr = nullptr; } // add to P0057?
  31   explicit operator bool() const { return ptr; }
  32
  33 protected:
  34   void *ptr;
  35 };
  36
  37 template <typename Promise> struct coroutine_handle : coroutine_handle<> {
  38   using coroutine_handle<>::operator=;
  39
  40   static coroutine_handle from_address(void *addr) noexcept {
  41     coroutine_handle me;
  42     me.ptr = addr;
  43     return me;
  44   }
  45
  46   Promise &promise() const {
  47     return *reinterpret_cast<Promise *>(
  48         __builtin_coro_promise(ptr, alignof(Promise), false));
  49   }
  50   static coroutine_handle from_promise(Promise &promise) {
  51     coroutine_handle p;
  52     p.ptr = __builtin_coro_promise(&promise, alignof(Promise), true);
  53     return p;
  54   }
  55 };
  56
  57 struct suspend_always {
  58   bool await_ready() { return false; }
  59   void await_suspend(coroutine_handle<>) {}
  60   void await_resume() {}
  61 };
  62
  63 struct suspend_never {
  64   bool await_ready() noexcept { return true; }
  65   void await_suspend(coroutine_handle<>) noexcept {}
  66   void await_resume() noexcept {}
  67 };
  68
  69 } // namespace std
  70
  71 #endif // STD_COROUTINE_H