A compressed pair. More...

#include <compressed_pair.hpp>

Inheritance diagram for entt::compressed_pair< First, Second >:

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Collaboration diagram for entt::compressed_pair< First, Second >:

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Public Types
using	first_type = First
	The type of the first element that the pair stores.

using	second_type = Second
	The type of the second element that the pair stores.

Public Member Functions
template<bool Dummy = true, typename = std::enable_if_t<Dummy && std::is_default_constructible_v<first_type> && std::is_default_constructible_v<second_type>>>
constexpr	compressed_pair () noexcept(std::is_nothrow_default_constructible_v< first_base > &&std::is_nothrow_default_constructible_v< second_base >)
	Default constructor, conditionally enabled.

constexpr	compressed_pair (const compressed_pair &other)=default
	Copy constructor.

constexpr	compressed_pair (compressed_pair &&other) noexcept=default
	Move constructor.

template<typename Arg, typename Other>
constexpr	compressed_pair (Arg &&arg, Other &&other) noexcept(std::is_nothrow_constructible_v< first_base, Arg > &&std::is_nothrow_constructible_v< second_base, Other >)
	Constructs a pair from its values.

template<typename... Args, typename... Other>
constexpr	compressed_pair (std::piecewise_construct_t, std::tuple< Args... > args, std::tuple< Other... > other) noexcept(std::is_nothrow_constructible_v< first_base, Args... > &&std::is_nothrow_constructible_v< second_base, Other... >)
	Constructs a pair by forwarding the arguments to its parts.

	~compressed_pair ()=default
	Default destructor.

constexpr compressed_pair &	operator= (const compressed_pair &other)=default
	Copy assignment operator.

constexpr compressed_pair &	operator= (compressed_pair &&other) noexcept=default
	Move assignment operator.

constexpr first_type &	first () noexcept
	Returns the first element that a pair stores.

constexpr const first_type &	first () const noexcept
	Returns the first element that a pair stores.

constexpr second_type &	second () noexcept
	Returns the second element that a pair stores.

constexpr const second_type &	second () const noexcept
	Returns the second element that a pair stores.

constexpr void	swap (compressed_pair &other) noexcept
	Swaps two compressed pair objects.

template<std::size_t Index>
constexpr decltype(auto)	get () noexcept
	Extracts an element from the compressed pair.

template<std::size_t Index>
constexpr decltype(auto)	get () const noexcept
	Extracts an element from the compressed pair.

Detailed Description

template<typename First, typename Second>
class entt::compressed_pair< First, Second >

A compressed pair.

A pair that exploits the Empty Base Class Optimization (or EBCO) to reduce its final size to a minimum.

Template Parameters

First	The type of the first element that the pair stores.
Second	The type of the second element that the pair stores.

Definition at line 85 of file compressed_pair.hpp.

Member Typedef Documentation

◆ first_type

template<typename First, typename Second>

using entt::compressed_pair< First, Second >::first_type = First

The type of the first element that the pair stores.

Definition at line 93 of file compressed_pair.hpp.

◆ second_type

template<typename First, typename Second>

using entt::compressed_pair< First, Second >::second_type = Second

The type of the second element that the pair stores.

Definition at line 95 of file compressed_pair.hpp.

Constructor & Destructor Documentation

◆ compressed_pair() [1/5]

template<typename First, typename Second>

template<bool Dummy = true, typename = std::enable_if_t<Dummy && std::is_default_constructible_v<first_type> && std::is_default_constructible_v<second_type>>>

entt::compressed_pair< First, Second >::compressed_pair ( )

inlineconstexprnoexcept

Default constructor, conditionally enabled.

This constructor is only available when the types that the pair stores are both at least default constructible.

Template Parameters

Dummy Dummy template parameter used for internal purposes.

Definition at line 106 of file compressed_pair.hpp.

◆ compressed_pair() [2/5]

template<typename First, typename Second>

entt::compressed_pair< First, Second >::compressed_pair ( const compressed_pair< First, Second > & other )

constexprdefault

Copy constructor.

Parameters

other The instance to copy from.

◆ compressed_pair() [3/5]

template<typename First, typename Second>

entt::compressed_pair< First, Second >::compressed_pair ( compressed_pair< First, Second > && other )

constexprdefaultnoexcept

Move constructor.

Parameters

other The instance to move from.

◆ compressed_pair() [4/5]

template<typename First, typename Second>

template<typename Arg, typename Other>

entt::compressed_pair< First, Second >::compressed_pair	(	Arg &&	arg,
		Other &&	other )

inlineconstexprnoexcept

Constructs a pair from its values.

Template Parameters

Arg	Type of value to use to initialize the first element.
Other	Type of value to use to initialize the second element.

Parameters

arg	Value to use to initialize the first element.
other	Value to use to initialize the second element.

Definition at line 130 of file compressed_pair.hpp.

◆ compressed_pair() [5/5]

template<typename First, typename Second>

template<typename... Args, typename... Other>

entt::compressed_pair< First, Second >::compressed_pair	(	std::piecewise_construct_t	,
		std::tuple< Args... >	args,
		std::tuple< Other... >	other )

inlineconstexprnoexcept

Constructs a pair by forwarding the arguments to its parts.

Template Parameters

Args	Types of arguments to use to initialize the first element.
Other	Types of arguments to use to initialize the second element.

Parameters

args	Arguments to use to initialize the first element.
other	Arguments to use to initialize the second element.

Definition at line 142 of file compressed_pair.hpp.

Member Function Documentation

◆ first() [1/2]

template<typename First, typename Second>

const first_type & entt::compressed_pair< First, Second >::first ( ) const

inlinenodiscardconstexprnoexcept

Returns the first element that a pair stores.

Returns: The first element that a pair stores.

Definition at line 172 of file compressed_pair.hpp.

◆ first() [2/2]

template<typename First, typename Second>

first_type & entt::compressed_pair< First, Second >::first ( )

inlinenodiscardconstexprnoexcept

Returns the first element that a pair stores.

Returns: The first element that a pair stores.

Definition at line 167 of file compressed_pair.hpp.

◆ get() [1/2]

template<typename First, typename Second>

template<std::size_t Index>

decltype(auto) entt::compressed_pair< First, Second >::get ( ) const

inlinenodiscardconstexprnoexcept

Extracts an element from the compressed pair.

Template Parameters

Index An integer value that is either 0 or 1.

Returns: Returns a reference to the first element if Index is 0 and a reference to the second element if Index is 1.

Definition at line 217 of file compressed_pair.hpp.

◆ get() [2/2]

template<typename First, typename Second>

template<std::size_t Index>

decltype(auto) entt::compressed_pair< First, Second >::get ( )

inlinenodiscardconstexprnoexcept

Extracts an element from the compressed pair.

Template Parameters

Index An integer value that is either 0 or 1.

Returns: Returns a reference to the first element if Index is 0 and a reference to the second element if Index is 1.

Definition at line 206 of file compressed_pair.hpp.

◆ operator=() [1/2]

template<typename First, typename Second>

compressed_pair & entt::compressed_pair< First, Second >::operator= ( compressed_pair< First, Second > && other )

constexprdefaultnoexcept

Move assignment operator.

Parameters

other The instance to move from.

Returns: This compressed pair object.

◆ operator=() [2/2]

template<typename First, typename Second>

compressed_pair & entt::compressed_pair< First, Second >::operator= ( const compressed_pair< First, Second > & other )

constexprdefault

Copy assignment operator.

Parameters

other The instance to copy from.

Returns: This compressed pair object.

◆ second() [1/2]

template<typename First, typename Second>

const second_type & entt::compressed_pair< First, Second >::second ( ) const

inlinenodiscardconstexprnoexcept

Returns the second element that a pair stores.

Returns: The second element that a pair stores.

Definition at line 185 of file compressed_pair.hpp.

◆ second() [2/2]

template<typename First, typename Second>

second_type & entt::compressed_pair< First, Second >::second ( )

inlinenodiscardconstexprnoexcept

Returns the second element that a pair stores.

Returns: The second element that a pair stores.

Definition at line 180 of file compressed_pair.hpp.

◆ swap()

template<typename First, typename Second>

void entt::compressed_pair< First, Second >::swap ( compressed_pair< First, Second > & other )

inlineconstexprnoexcept

Swaps two compressed pair objects.

Parameters

other The compressed pair to swap with.

Definition at line 193 of file compressed_pair.hpp.

The documentation for this class was generated from the following file:

src/entt/core/compressed_pair.hpp

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ first_type

◆ second_type

Constructor & Destructor Documentation

◆ compressed_pair() [1/5]

◆ compressed_pair() [2/5]

◆ compressed_pair() [3/5]

◆ compressed_pair() [4/5]

◆ compressed_pair() [5/5]

Member Function Documentation

◆ first() [1/2]

◆ first() [2/2]

◆ get() [1/2]

◆ get() [2/2]

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ second() [1/2]

◆ second() [2/2]

◆ swap()