jh::concepts::sentinel_for Concept Reference

Concept for detecting sentinel-iterator compatibility. More...

#include <jh/conceptual/iterator.h>

Concept definition

    template<typename S, typename I>
    concept sentinel_for =requires(const S &s, const I &i) {
        { i == s } -> std::convertible_to<bool>;
        { s == i } -> std::convertible_to<bool>;
        { i != s } -> std::convertible_to<bool>;
        { s != i } -> std::convertible_to<bool>;
    }

Detailed Description

Concept for detecting sentinel-iterator compatibility.

• Checks only mutual equality and inequality between S and I (== and !=), ensuring both directions are valid and convertible to bool.
• Unlike the STL's std::sentinel_for, this concept is more permissive: it does not require specific construction, iterator traits, or range category relationships.
• Intended for lightweight duck-typed iteration boundaries where full STL conformance is unnecessary.

Template Parameters

S	Sentinel type to compare against an iterator.
I	Iterator-like type to be checked for compatibility with S.