jh::concepts::sequence Concept Reference

Concept that checks whether a type provides at least const (non-destructive) iteration. More...

#include <jh/conceptual/sequence.h>

Concept definition

    template<typename T>
    concept sequence = requires(const T &t)
    {
        { std::begin(t) } -> input_iterator;
        { std::end(t) };
        { std::begin(t) == std::end(t) } -> std::convertible_to<bool>;
        { std::begin(t) != std::end(t) } -> std::convertible_to<bool>;
    }

Detailed Description

Concept that checks whether a type provides at least const (non-destructive) iteration.

A type T satisfies jh::concepts::sequence if:

1. It provides begin() and end() that can be called on a const T&.
2. The returned iterators satisfy jh::input_iterator.
3. begin() and end() are comparable for equality and inequality.

The concept requires that iteration be non-destructive — traversing the sequence must not modify or consume its internal state.

The type must support at least const iteration (i.e. traversal through const T&), but may also provide mutable iteration (T&). In other words, a sequence represents any type that can be iterated safely multiple times without state consumption, regardless of whether its elements themselves are mutable.

Template Parameters

T	The candidate type to test for sequence behavior.