constexpr coroutine_handle() noexcept;
constexpr coroutine_handle(nullptr_t) noexcept;
static coroutine_handle from_promise(Promise& p);
coroutine_handle& operator=(nullptr_t) noexcept;
constexpr operator coroutine_handle<>() const noexcept;
constexpr void* address() const noexcept;
static constexpr coroutine_handle<> coroutine_handle<>::from_address(void* addr);
static constexpr coroutine_handle<Promise> coroutine_handle<Promise>::from_address(void* addr);
constexpr explicit operator bool() const noexcept;
bool done() const;
void operator()() const;
void resume() const;
void destroy() const;
Promise& promise() const;
constexpr bool operator==(coroutine_handle<> x, coroutine_handle<> y) noexcept;
constexpr strong_ordering operator<=>(coroutine_handle<> x, coroutine_handle<> y) noexcept;
template<class P> struct hash<coroutine_handle<P>>;
struct noop_coroutine_promise {};
constexpr operator coroutine_handle<>() const noexcept;
constexpr explicit operator bool() const noexcept;
constexpr bool done() const noexcept;
constexpr void operator()() const noexcept;
constexpr void resume() const noexcept;
constexpr void destroy() const noexcept;
noop_coroutine_promise& promise() const noexcept;
constexpr void* address() const noexcept;
noop_coroutine_handle noop_coroutine() noexcept;