Manages an optional contained value, i.e. a value that may or may not be present. More...

#include <nullable.hpp>

Public Member Functions
constexpr	Nullable ()
	Constructs a `Nullable` that represents the absence of value.

constexpr	Nullable (T initialValue) noexcept(std::is_nothrow_move_constructible< T >::value)
	Constructs a `Nullable` having an `initialValue`.

	Nullable (const Nullable &other) noexcept(std::is_nothrow_copy_constructible< T >::value)
	Constructs a `Nullable` by copying another `Nullable`.

	Nullable (Nullable &&other) noexcept(std::is_nothrow_move_constructible< T >::value)
	Constructs a `Nullable` by moving in another `Nullable`.

	~Nullable ()
	Destructs the `Nullable`, calling the destructor for the contained value if there is one.

void	Reset () noexcept(std::is_nothrow_destructible< T >::value)
	Destructs the contained value, if there is one.

void	Swap (Nullable &other) noexcept(std::is_nothrow_move_constructible< T >::value)
	Exchanges the contents.

Nullable &	operator= (const Nullable &other)
	Assignment operator.

Nullable &	operator= (Nullable &&other) noexcept(std::is_nothrow_move_constructible< T >::value)
	Assignment operator with move semantics.

template<class U = T, typename std::enable_if< !std::is_same< Nullable, typename std::remove_cv< typename std::remove_reference< U >::type >::type >::value &&!(std::is_scalar< U >::value &&std::is_same< T, typename std::decay< U >::type >::value) &&std::is_constructible< T, U >::value &&std::is_assignable< T &, U >::value, int >::type = 0>
Nullable &	operator= (U &&other) noexcept(std::is_nothrow_constructible< T, U >::value &&std::is_nothrow_assignable< T &, U >::value)
	Assignment operator from another type.

template<class... U>
T &	Emplace (U &&... Args) noexcept(std::is_nothrow_constructible< T, U... >::value)
	Construct the contained value in-place.

bool	HasValue () const noexcept
	Check whether a value is contained.

const T &	Value () const &noexcept
	Get the contained value.

T &	Value () &noexcept
	Get the contained value reference.

T &&	Value () &&noexcept
	Get the contained value (as rvalue reference).

constexpr	operator bool () const noexcept
	`operator bool` on the condition of Azure::Nullable::HasValue.

constexpr const T *	operator-> () const
	Accesses the contained value.

constexpr T *	operator-> ()
	Accesses the contained value.

constexpr const T &	operator* () const &
	Accesses the contained value.

constexpr T &	operator* () &
	Accesses the contained value.

constexpr T &&	operator* () &&
	Accesses the contained value.

constexpr const T &&	operator* () const &&
	Accesses the contained value.

template<class U = T, typename std::enable_if< std::is_convertible< const T &, typename std::remove_cv< T >::type >::value &&std::is_convertible< U, T >::value, int >::type = 0>
constexpr std::remove_cv< T >::type	ValueOr (U &&other) const &
	Get the contained value, returns `other` if value is absent.

template<class U = T, typename std::enable_if< std::is_convertible< T, typename std::remove_cv< T >::type >::value &&std::is_convertible< U, T >::value, int >::type = 0>
constexpr std::remove_cv< T >::type	ValueOr (U &&other) &&
	Get the contained value, returns `other` if value is absent.

Friends
void	swap (Nullable &lhs, Nullable &rhs) noexcept(std::is_nothrow_move_constructible< T >::value)
	Invokes Azure::Nullable::Swap while having a lowercase name that satisfies `swappable` requirements (see details).

Detailed Description

template<class T>
class Azure::Nullable< T >

Template Parameters

T	A type to represent contained values.

Constructor & Destructor Documentation

◆ Nullable() [1/4]

template<class T >

constexpr Azure::Nullable< T >::Nullable ( )

inlineconstexpr

◆ Nullable() [2/4]

template<class T >

constexpr Azure::Nullable< T >::Nullable ( T initialValue )

inlineconstexprnoexcept

Parameters

initialValue A non-absent value to initialize with.

◆ Nullable() [3/4]

template<class T >

Azure::Nullable< T >::Nullable ( const Nullable< T > & other )

inlinenoexcept

Parameters

other Another Nullable instance to copy.

◆ Nullable() [4/4]

template<class T >

Azure::Nullable< T >::Nullable ( Nullable< T > && other )

inlinenoexcept

Parameters

other A Nullable instance to move into the instance being constructed.

◆ ~Nullable()

template<class T >

Azure::Nullable< T >::~Nullable ( )

inline

Member Function Documentation

◆ Emplace()

template<class T >

template<class... U>

T & Azure::Nullable< T >::Emplace ( U &&... Args )

inlinenoexcept

If this instance already contains a value before the call, the contained value is destroyed by calling its destructor.

◆ HasValue()

template<class T >

bool Azure::Nullable< T >::HasValue ( ) const

inlinenoexcept

Returns: true If a value is contained, false if value is absent.

◆ operator bool()

template<class T >

constexpr Azure::Nullable< T >::operator bool ( ) const

inlineexplicitconstexprnoexcept

◆ operator*() [1/4]

template<class T >

constexpr T & Azure::Nullable< T >::operator* ( ) &

inlineconstexpr

Returns: Returns a reference to the contained value.

Warning: The behavior is undefined if *this does not contain a value.

Note: This operator does not check whether the Nullable contains a value! You can do so manually by using HasValue() or simply operator bool(). Alternatively, if checked access is needed, Value() or ValueOr() may be used.

◆ operator*() [2/4]

template<class T >

constexpr T && Azure::Nullable< T >::operator* ( ) &&

inlineconstexpr

Returns: Returns a reference to the contained value.

Warning: The behavior is undefined if *this does not contain a value.

Note: This operator does not check whether the Nullable contains a value! You can do so manually by using HasValue() or simply operator bool(). Alternatively, if checked access is needed, Value() or ValueOr() may be used.

◆ operator*() [3/4]

template<class T >

constexpr const T & Azure::Nullable< T >::operator* ( ) const &

inlineconstexpr

Returns: Returns a reference to the contained value.

Warning: The behavior is undefined if *this does not contain a value.

Note: This operator does not check whether the Nullable contains a value! You can do so manually by using HasValue() or simply operator bool(). Alternatively, if checked access is needed, Value() or ValueOr() may be used.

◆ operator*() [4/4]

template<class T >

constexpr const T && Azure::Nullable< T >::operator* ( ) const &&

inlineconstexpr

Returns: Returns a reference to the contained value.

Warning: The behavior is undefined if *this does not contain a value.

Note: This operator does not check whether the Nullable contains a value! You can do so manually by using HasValue() or simply operator bool(). Alternatively, if checked access is needed, Value() or ValueOr() may be used.

◆ operator->() [1/2]

template<class T >

constexpr T * Azure::Nullable< T >::operator-> ( )

inlineconstexpr

Returns: Returns a pointer to the contained value.

Warning: The behavior is undefined if *this does not contain a value.

Note: This operator does not check whether the Nullable contains a value! You can do so manually by using HasValue() or simply operator bool(). Alternatively, if checked access is needed, Value() or ValueOr() may be used.

◆ operator->() [2/2]

template<class T >

constexpr const T * Azure::Nullable< T >::operator-> ( ) const

inlineconstexpr

Returns: Returns a pointer to the contained value.

Warning: The behavior is undefined if *this does not contain a value.

Note: This operator does not check whether the Nullable contains a value! You can do so manually by using HasValue() or simply operator bool(). Alternatively, if checked access is needed, Value() or ValueOr() may be used.

◆ operator=()

template<class T >

template<class U = T, typename std::enable_if< !std::is_same< Nullable, typename std::remove_cv< typename std::remove_reference< U >::type >::type >::value &&!(std::is_scalar< U >::value &&std::is_same< T, typename std::decay< U >::type >::value) &&std::is_constructible< T, U >::value &&std::is_assignable< T &, U >::value, int >::type = 0>

Nullable & Azure::Nullable< T >::operator= ( U && other )

inlinenoexcept

Template Parameters

U	Type of `other`.

Parameters

other Other Azure::Nullable.

◆ Reset()

template<class T >

void Azure::Nullable< T >::Reset ( )

inlinenoexcept

◆ Swap()

template<class T >

void Azure::Nullable< T >::Swap ( Nullable< T > & other )

inlinenoexcept

Parameters

other An instance to exchange the contents with.

◆ Value() [1/3]

template<class T >

T && Azure::Nullable< T >::Value ( ) &&

inlinenoexcept

◆ Value() [2/3]

template<class T >

T & Azure::Nullable< T >::Value ( ) &

inlinenoexcept

◆ Value() [3/3]

template<class T >

const T & Azure::Nullable< T >::Value ( ) const &

inlinenoexcept

◆ ValueOr() [1/2]

template<class T >

template<class U = T, typename std::enable_if< std::is_convertible< T, typename std::remove_cv< T >::type >::value &&std::is_convertible< U, T >::value, int >::type = 0>

constexpr std::remove_cv< T >::type Azure::Nullable< T >::ValueOr ( U && other ) &&

inlineconstexpr

Parameters

other A value to return when no value is contained.

Returns: A contained value (when present), or other.

◆ ValueOr() [2/2]

template<class T >

template<class U = T, typename std::enable_if< std::is_convertible< const T &, typename std::remove_cv< T >::type >::value &&std::is_convertible< U, T >::value, int >::type = 0>

constexpr std::remove_cv< T >::type Azure::Nullable< T >::ValueOr ( U && other ) const &

inlineconstexpr

Parameters

other A value to return when no value is contained.

Returns: A contained value (when present), or other.

Friends And Related Symbol Documentation

◆ swap

template<class T >

void swap	(	Nullable< T > &	lhs,
		Nullable< T > &	rhs
	)

friend

Swappable requirements: https://en.cppreference.com/w/cpp/named_req/Swappable

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

inc/azure/core/nullable.hpp

Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Nullable() [1/4]

◆ Nullable() [2/4]

◆ Nullable() [3/4]

◆ Nullable() [4/4]

◆ ~Nullable()

Member Function Documentation

◆ Emplace()

◆ HasValue()

◆ operator bool()

◆ operator*() [1/4]

◆ operator*() [2/4]

◆ operator*() [3/4]

◆ operator*() [4/4]

◆ operator->() [1/2]

◆ operator->() [2/2]

◆ operator=()

◆ Reset()

◆ Swap()

◆ Value() [1/3]

◆ Value() [2/3]

◆ Value() [3/3]

◆ ValueOr() [1/2]

◆ ValueOr() [2/2]

Friends And Related Symbol Documentation

◆ swap