std::basic_common_reference<tuple-like> - cppreference.com

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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 [0std::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 [0std::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>>...>

Example

See also