std::common_type<tuple-like>

 

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Defined in header <tuple>
template< /*tuple-like*/ TTuple, /*tuple-like*/ UTuple >     requires /* see below */ struct common_type<TTuple, UTuple>;		(since C++23)

The common type of two tuple-like types is a tuple consists of the common types of all corresponding element type pairs of both types.

The common type is defined only if

• both TTuple and UTuple are cv-unqualified tuple-like types, and
• either TTuple or UTuple is a std::tuple specialization, and
• both TTuple and UTuple have the same number of elements (as determined by std::tuple_size_v), and
• all corresponding element type pairs of TTuple and UTuple have common types.

Member types

Member type	Definition
type	std::tuple<std::common_type_t<TTypes, UTypes>...>

In the table above, TTypes... and UTypes... denotes the sequence of element types of TTuple and UTuple respectively, where each elements type of TupleLike at given index I is std::tuple_element_t<I, TupleLike>.

See also

common_type (C++11)	determines the common type of a group of types (class template)
std::common_type<std::pair> (C++23)	determines the common type of two pairs (class template specialization)