template <class F, class... Args>
concept bool RegularInvocable =
Invocable<F, Args...>;
The invoke function call expression shall be equality-preserving and shall not modify the function object or the arguments ([concepts.lib.general.equality]). [ Note: This requirement supersedes the annotation in the definition of Invocable. — end note ]
[ Note: A random number generator does not satisfy RegularInvocable. — end note ]
[ Note: The distinction between Invocable and RegularInvocable is purely semantic. — end note ]