std::mergeable - cppreference.com

From cppreference.com

template< class I1, class I2, class Out, class Comp = ranges::less, class Proj1 = std::identity, class Proj2 = std::identity > concept mergeable = std::input_iterator<I1> && std::input_iterator<I2> && std::weakly_incrementable<Out> && std::indirectly_copyable<I1, Out> && std::indirectly_copyable<I2, Out> && std::indirect_strict_weak_order<Comp, std::projected<I1, Proj1>, std::projected<I2, Proj2>>;

(since C++20)

The mergeable concept specifies the requirements for algorithms that merge two input ranges into a single output range according to the strict weak ordering imposed by Comp.

Semantic requirements

mergeable is modeled only if all concepts it subsumes are modeled.

See also