26 Ranges library [ranges]

26.8 Range generators [coro.generator]

26.8.3 Class template generator [coro.generator.class]

namespace std { template<class Ref, class V = void, class Allocator = void> class generator : public ranges::view_interface<generator<Ref, V, Allocator>> { private: using value = conditional_t<is_void_v<V>, remove_cvref_t<Ref>, V>; // exposition only using reference = conditional_t<is_void_v<V>, Ref&&, Ref>; // exposition only // [coro.generator.iterator], class generator​::​iterator class iterator; // exposition only public: using yielded = conditional_t<is_reference_v<reference>, reference, const reference&>; // [coro.generator.promise], class generator​::​promise_type class promise_type; generator(const generator&) = delete; generator(generator&& other) noexcept; ~generator(); generator& operator=(generator other) noexcept; iterator begin(); default_sentinel_t end() const noexcept; private: coroutine_handle<promise_type> coroutine_ = nullptr; // exposition only unique_ptr<stack<coroutine_handle<>>> active_; // exposition only }; }
If Allocator is not void, it shall meet the Cpp17Allocator requirements.
Specializations of generator model view and input_range.
The behavior of a program that adds a specialization for generator is undefined.