std::experimental::ranges::TaggedType

From cppreference.com
< cpplrm; | experimentallrm; | ranges
template< class T >
concept bool TaggedType = /* implementation-defined */;
(ranges TS)

The concept TaggedType<T> is satisfied if and only if T is a unary function type of the form R(A), where R is a TagSpecifier.

Such types are used with the convenience alias templates tagged_tuple and tagged_pair.

See also

alias template for a tagged std::tuple
(alias template)
alias template for a tagged std::pair
(alias template)
tag specifiers for use with ranges::tagged
(class)