std::stoppable_token

Since C++26

Header: <stop_token>

The concept stoppable_token specifies the basic interface of a stop token that is copyable and equality_comparable and allows polling to see if the stop request is possible and whether the request has been made.

# Declarations

template< class Token >
concept stoppable_token =
requires (const Token tok) {
typename /*check-type-alias-exists*/<Token::template callback_type>;
{ tok.stop_requested() } noexcept -> std::same_as<bool>;
{ tok.stop_possible() } noexcept -> std::same_as<bool>;
{ Token(tok) } noexcept; // see implicit expression variations
} &&
std::copyable<Token> &&
std::equality_comparable<Token>;

(since C++26)

Helper templates

template< template<class> class >
struct /*check-type-alias-exists*/; // not defined

(exposition only*)

# See also