<utility>

Defines C++ Standard Library types, functions, and operators that help to construct and manage pairs of objects, which are useful whenever two objects need to be treated as if they were one.

Requirements

Header: <utility>

Namespace: std

Remarks

Pairs are widely used in the C++ Standard Library. They are required both as the arguments and return values for various functions and as element types for containers such as map class and multimap class. The <utility> header is automatically included by <map> to assist in managing their key/value pair type elements.

Note

The <utility> header uses the statement #include <initializer_list>. It also refers to class tuple as defined in <tuple>.

Members

Classes

chars_format Floating-point format for primitive numerical conversion.
tuple_element A class that wraps the type of a pair element.
tuple_size A class that wraps pair element count.

Objects

index_sequence
index_sequence_for
make_index_sequence
make_integer_sequence

Functions

as_const Returns type.
declval Shorthand expression evaluation.
exchange Assigns a new value to an object and returns its old value.
forward Preserves the reference type (either lvalue or rvalue) of the argument from being obscured by perfect forwarding.
from_chars
get A function that gets an element from a pair object.
make_pair A template helper function used to construct objects of type pair, where the component types are based on the data types passed as parameters.
move Returns the passed in argument as an rvalue reference.
move_if_noexcept
swap Exchanges the elements of two pair objects.
to_chars Converts value into a character string.

Operators

operator!= Tests if the pair object on the left side of the operator is not equal to the pair object on the right side.
operator== Tests if the pair object on the left side of the operator is equal to the pair object on the right side.
operator< Tests if the pair object on the left side of the operator is less than the pair object on the right side.
operator<= Tests if the pair object on the left side of the operator is less than or equal to the pair object on the right side.
operator> Tests if the pair object on the left side of the operator is greater than the pair object on the right side.
operator>= Tests if the pair object on the left side of the operator is greater than or equal to the pair object on the right side.

Structs

from_chars_result A struct used for from_chars.
identity A struct that provides a type definition as the template parameter.
in_place_t Also includes structs in_place_type_t and in_place_index_t.
integer_sequence Represents an integer sequence.
pair A type that provides for the ability to treat two objects as a single object.
piecewise_construct_t A type used to keep separate constructor and function overloading.
to_chars_result A struct used for to_chars.

See also

Header Files Reference
Thread Safety in the C++ Standard Library