< cpp‎ | experimental‎ | ranges
Technical specifications
Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals 2 TS)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Concepts (concepts TS)
Ranges (ranges TS)
Special mathematical functions (special math TR)
Iterators library
Iterator concepts
Indirect callable concepts
Common algorithm requirements
Concept utilities
Iterator utilities and operations
Iterator traits
Iterator adaptors
Stream iterators
template < class S, class I >

concept bool Sentinel =
  ranges::Semiregular<S> && ranges::Iterator<I> &&

  ranges::WeaklyEqualityComparableWith<S, I>;
(ranges TS)

The Sentinel concept specifies the relationship between an Iterator type and a Semiregular type whose values denote a range.

Let s and i be values of type S and I, respectively, such that [i, s) denotes a range. Sentinel<S, I> is satisfied only if:

  • i == s is well-defined.
  • If bool(i != s) then i is dereferenceable and [++i, s) denotes a range.

The domain of == can change over time. Given an iterator i and sentinel s such that [i, s) denotes a range and i != s, [i, s) is not required to continue to denote a range after incrementing any iterator equal to i (and so i == s is no longer required to be well-defined after such an increment).