17 Language support library [language.support]

17.12 Coroutines [support.coroutine]

17.12.4 No-op coroutines [coroutine.noop]

17.12.4.2 Class coroutine_­handle<noop_­coroutine_­promise> [coroutine.handle.noop]

17.12.4.2.1 Observers [coroutine.handle.noop.observers]

constexpr explicit operator bool() const noexcept;
Returns: true.
constexpr bool done() const noexcept;
Returns: false.