servlet::optional_ref< T > Class Template Reference

Optional reference implementation. More...

#include <optional.h>

Public Types
typedef T	value_type
	Type definition for value type.
typedef T &	reference
	Type definition for reference type.
typedef const T &	const_reference
	Type definition for constant reference type.

Public Member Functions
constexpr	optional_ref () noexcept
	Default constructor. More...
constexpr	optional_ref (T &obj) noexcept
	Constructs object that contains a reference to a given object,. More...
constexpr	optional_ref (const optional_ref &other) noexcept
	Copy constructor. More...
constexpr	optional_ref (optional_ref &&other) noexcept
	Move constructor. More...
	~optional_ref () noexcept
	Destructor. More...
constexpr optional_ref &	operator= (const optional_ref &other) noexcept
	Replaces contents of this object with the contents of other. More...
constexpr optional_ref &	operator= (optional_ref &&other) noexcept
	Move assignment. More...
constexpr optional_ref &	operator= (T &obj) noexcept
	Replaces contents of this object with the reference to other. More...
constexpr T *	operator-> ()
	Accesses the contained value as a pointer. More...
constexpr const T *	operator-> () const
	Accesses the contained value as a constant pointer. More...
constexpr T &	operator* ()
	Accesses the contained value as a reference. More...
constexpr const T &	operator* () const
	Accesses the contained value as a constant reference. More...
constexpr	operator bool () const noexcept
	Checks whether this object contains valid pointer. More...
constexpr bool	has_value () const noexcept
	Checks whether this object contains valid pointer. More...
constexpr T &	value ()&
	Accesses the contained value as a reference. More...
constexpr const T &	value () const &
	Accesses the contained value as a constant reference. More...
template<typename OT >
constexpr T	value_or (OT &&dflt) const &noexcept
	Returns the contained value if this has a value, otherwise returns given value. More...
constexpr void	swap (optional_ref &other) noexcept
	Swaps the contents with those of other. More...
constexpr void	reset () noexcept
	If this object contains a reference to an object, reset the pointer to that to nullptr. More...

Detailed Description

template<typename T>
class servlet::optional_ref< T >

Optional reference implementation.

It is resambles std::optional but doesn't copy the object, instead it stores the reference to the object and never attempts to destroy it. This object might be usefull when returning the object from container and it is not known up front if this object exists.

Template Parameters

the	type of the value to manage.

Constructor & Destructor Documentation

template<typename T>

constexpr servlet::optional_ref< T >::optional_ref ( )

inlinenoexcept

Default constructor.

Constructs the object that does not contain a reference to any value.

template<typename T>

constexpr servlet::optional_ref< T >::optional_ref ( T &  obj )

inlinenoexcept

Constructs object that contains a reference to a given object,.

Parameters

obj	Object to whcih this object will refere.

template<typename T>

constexpr servlet::optional_ref< T >::optional_ref ( const optional_ref< T > &  other )

inlinenoexcept

Copy constructor.

Parameters

other

object to copy.

template<typename T>

constexpr servlet::optional_ref< T >::optional_ref ( optional_ref< T > &&  other )

inlinenoexcept

Move constructor.

Parameters

other

object to move.

template<typename T>

servlet::optional_ref< T >::~optional_ref ( )

inlinenoexcept

Destructor.

Does nothing.

Member Function Documentation

template<typename T>

constexpr bool servlet::optional_ref< T >::has_value ( ) const

inlinenoexcept

Checks whether this object contains valid pointer.

Returns

true if this object contains valid pointer, false otherwise.

template<typename T>

constexpr servlet::optional_ref< T >::operator bool ( ) const

inlineexplicitnoexcept

Checks whether this object contains valid pointer.

Returns

true if this object contains valid pointer, false otherwise.

See Also

has_value

template<typename T>

constexpr T& servlet::optional_ref< T >::operator* ( )

inline

Accesses the contained value as a reference.

Returns

a reference to the contained value.

Exceptions

null_pointer_exception

if the contained pointer is nullptr.

template<typename T>

constexpr const T& servlet::optional_ref< T >::operator* ( ) const

inline

Accesses the contained value as a constant reference.

Returns

a const reference to the contained value.

Exceptions

null_pointer_exception

if the contained pointer is nullptr.

template<typename T>

constexpr T* servlet::optional_ref< T >::operator-> ( )

inline

Accesses the contained value as a pointer.

Returns

a pointer to the contained value.

Exceptions

null_pointer_exception

if the contained pointer is nullptr.

template<typename T>

constexpr const T* servlet::optional_ref< T >::operator-> ( ) const

inline

Accesses the contained value as a constant pointer.

Returns

a const pointer to the contained value.

Exceptions

null_pointer_exception

if the contained pointer is nullptr.

template<typename T>

constexpr optional_ref& servlet::optional_ref< T >::operator= ( const optional_ref< T > &  other )

inlinenoexcept

Replaces contents of this object with the contents of other.

Parameters

other

object to assign

Returns

self

template<typename T>

constexpr optional_ref& servlet::optional_ref< T >::operator= ( optional_ref< T > &&  other )

inlinenoexcept

Move assignment.

Parameters

other

object to assign

Returns

self

template<typename T>

constexpr optional_ref& servlet::optional_ref< T >::operator= ( T &  obj )

inlinenoexcept

Replaces contents of this object with the reference to other.

Parameters

obj	object to refere

Returns

self

template<typename T>

constexpr void servlet::optional_ref< T >::reset ( )

inlinenoexcept

If this object contains a reference to an object, reset the pointer to that to nullptr.

Otherwise, there are no effects.

template<typename T>

constexpr void servlet::optional_ref< T >::swap ( optional_ref< T > &  other )

inlinenoexcept

Swaps the contents with those of other.

Parameters

other

the object to exchange the contents with

template<typename T>

constexpr T& servlet::optional_ref< T >::value ( )

inline

Accesses the contained value as a reference.

Returns

a reference to the contained value.

Exceptions

null_pointer_exception

if the contained pointer is nullptr.

template<typename T>

constexpr const T& servlet::optional_ref< T >::value ( ) const

inline

Accesses the contained value as a constant reference.

Returns

a const reference to the contained value.

Exceptions

null_pointer_exception

if the contained pointer is nullptr.

template<typename T>

template<typename OT >

constexpr T servlet::optional_ref< T >::value_or ( OT &&  dflt ) const

inlinenoexcept

Returns the contained value if this has a value, otherwise returns given value.

Parameters

dflt	the value to use in case this is empty

Returns

The current value if this has a value, or dflt otherwise.

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

• include/servlet/lib/optional.h