std::sized_sentinel_for, std::disable_sized_sentinel_for

Since C++20

Header: <iterator>

  1. The sized_sentinel_for concept specifies that an object of the iterator type I and an object of the sentinel type S can be subtracted to compute the distance between them in constant time.

# Declarations

template< class S, class I >
concept sized_sentinel_for =
std::sentinel_for<S, I> &&
!std::disable_sized_sentinel_for<std::remove_cv_t<S>,
std::remove_cv_t<I>> &&
requires(const I& i, const S& s) {
{ s - i } -> std::same_as<std::iter_difference_t<I>>;
{ i - s } -> std::same_as<std::iter_difference_t<I>>;
};

(since C++20)

template< class S, class I >
inline constexpr bool disable_sized_sentinel_for = false;

(since C++20)

# See also