std::pair

C++

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Technical Specifications

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Type support (basic types, RTTI, type traits)
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rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>=
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strong_order weak_order partial_order strong_equal weak_equal	strong_ordering weak_ordering partial_ordering strong_equality weak_equality	is_eqis_neqis_ltis_lteqis_gtis_gteq
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Common vocabulary types
pair tuple (C++11) apply (C++17) make_from_tuple (C++17)	optional (C++17) any (C++17) variant (C++17)
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swap
exchange (C++14)
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std::pair

Member functions

pair::pair

pair::operator=

pair::swap

Non-member functions

make_pair

operator==operator!=operator<operator<=operator>operator>=

std::swap

get (C++11)

Deduction guides(C++17)

Helper classes

tuple_size (C++11)

tuple_element (C++11)

Defined in header <utility>
template< class T1, class T2 > struct pair;

std::pair is a struct template that provides a way to store two heterogeneous objects as a single unit. A pair is a specific case of a std::tuple with two elements.

If std::is_trivially_destructible_v<T1> && std::is_trivially_destructible_v<T2> is true, the destructor of pair is trivial.

(since C++17)

Template parameters

T1, T2

-

the types of the elements that the pair stores.

Member types

Member type	Definition
first_type	T1
second_type	T2

Member objects

Member name	Type
first	T1
second	T2

Member functions

(constructor)	constructs new pair (public member function)
operator=	assigns the contents (public member function)
swap (C++11)	swaps the contents (public member function)

Non-member functions

make_pair	creates a pair object of type, defined by the argument types (function template)
operator==operator!=operator<operator<=operator>operator>=	lexicographically compares the values in the pair (function template)
std::swap(std::pair) (C++11)	specializes the std::swap algorithm (function template)
std::get(std::pair) (C++11)	accesses an element of a pair (function template)

Helper classes

std::tuple_size<std::pair> (C++11)	obtains the size of a pair (class template specialization)
std::tuple_element<std::pair> (C++11)	obtains the type of the elements of pair (class template specialization)

See also

tuple (C++11)	implements fixed size container, which holds elements of possibly different types (class template)
tie	creates a tuple of lvalue references or unpacks a tuple into individual objects (function template)