std::noop_coroutine

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Technical Specifications

 

Utilities library

Language support Type support (basic types, RTTI, type traits) Library feature-test macros (C++20) Dynamic memory management Program utilities Error handling Coroutine support (C++20) Variadic functions launder (C++17) initializer_list (C++11) source_location (C++20) Three-way comparison (C++20) three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20) is_eqis_neqis_ltis_lteqis_gtis_gteq (C++20)(C++20)(C++20)(C++20)(C++20)(C++20)

General utilities Date and time Function objects Formatting library (C++20) bitset hash (C++11) integer_sequence (C++14) Relational operators (deprecated in C++20) rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>= Integer comparison functions cmp_equalcmp_not_equalcmp_lesscmp_greatercmp_less_thancmp_greater_than (C++20)(C++20)(C++20)(C++20)(C++20)(C++20) in_range (C++20) Swap and type operations swap ranges::swap (C++20) exchange (C++14) declval (C++11) forward (C++11) move (C++11) move_if_noexcept (C++11) as_const (C++17) Common vocabulary types pair tuple (C++11) apply (C++17) make_from_tuple (C++17) optional (C++17) any (C++17) variant (C++17) Elementary string conversions to_chars (C++17) from_chars (C++17) chars_format (C++17)

 

Coroutine support

Coroutine traits

coroutine_traits (C++20)

Coroutine handle

coroutine_handle (C++20)

No-op coroutines

noop_coroutine_promise (C++20)

noop_coroutine (C++20)

Trivial awaitables

suspend_never (C++20)

suspend_always (C++20)

 

Defined in header <coroutine>
std::noop_coroutine_handle noop_coroutine() noexcept;		(since C++20)

Returns a coroutine handle referring to a no-op coroutine.

If there has been already a coroutine state of no-op coroutine, it is unspecified whether subsequent call to noop_coroutine returns a previously obtained coroutine handle, or a coroutine handle referring to a new coroutine state of no-op coroutine.

Parameters

(none)

Return value

A std::noop_coroutine_handle referring to a no-op coroutine.

Notes

Return values from different calls to noop_coroutine may and may not compare equal.

No-op coroutines are not required to be defined, and noop_coroutine may only return a noop_coroutine_handle referring to a coroutine state object without starting a coroutine.

See also

noop_coroutine_promise (C++20)	used for coroutines with no observable effects (class)
noop_coroutine_handle (C++20)	std::coroutine_handle<std::noop_coroutine_promise>, intended to refer to a no-op coroutine (typedef)