std::basic_common_reference<tuple-like>

 

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tuple-like (C++23)

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tuple_size<std::tuple>

tuple_element<std::tuple>

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basic_common_reference<std::tuple> (C++23)

common_type<std::tuple> (C++23)

formatter<std::tuple> (C++23)

ignore

Deduction guides(C++17)

 

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

The common reference type of two tuple-like types is a std::tuple consists of the common reference types of all corresponding element type pairs of both types, where the cv and reference qualifiers on the tuple-like types are applied to their element types.

Given

• TTypes as the pack formed by the sequence of std::tuple_element_t<i, TTuple> for every integer i in [0, std::tuple_size_v<TTuple>), and
• UTypes as the pack formed by the sequence of std::tuple_element_t<i, UTuple> for every integer i in [0, std::tuple_size_v<UTuple>),

the following constraints need to be satisfied:

• TTuple or UTuple is a std::tuple specialization.
• std::is_same_v<TTuple, std::decay_t<TTuple>> is true.
• std::is_same_v<UTuple, std::decay_t<UTuple>> is true.
• std::tuple_size_v<TTuple> equals std::tuple_size_v<UTuple> (TTuple and UTuple have the same number of elements).
• std::tuple<std::common_reference_t<TQual<TTypes>..., UQual<UTypes>>...> denotes a type.

Member types

Member type	Definition
type	std::tuple<std::common_reference_t<TQual<TTypes>..., UQual<UTypes>>...>

See also

common_referencebasic_common_reference (C++20)	determines the common reference type of a group of types (class template)
std::basic_common_reference<std::pair> (C++23)	determines the common reference type of two pairs (class template specialization)