hxref< T > Class Template Reference

#include <hxref.hpp>

Public Types
using	value_t = T&

Public Member Functions
	hxref (void)
	hxref (hxnil_t)
template<typename U_, hxenable_if_t< !hxis_hxref_< hxremove_cvref_t< U_ > >::value &&!hxis_hxexpected_< hxremove_cvref_t< U_ > >::value &&hxbinds_directly< T, U_ >(), bool > = true>
	hxref (U_ &value_)
template<typename E_>
	hxref (hxexpected< T, E_ > &x_)
T &	operator* (void) const
T *	operator-> (void) const
	operator bool (void) const
hxref &	operator= (hxnil_t)
template<typename U_, hxenable_if_t< !hxis_hxref_< hxremove_cvref_t< U_ > >::value &&!hxis_hxexpected_< hxremove_cvref_t< U_ > >::value &&hxbinds_directly< T, U_ >(), bool > = true>
hxref &	operator= (U_ &value_)
bool	operator== (const hxref &x_) const
bool	operator== (hxnil_t) const
bool	operator== (const T &value_) const
template<typename self_t_, typename callable_t_>
auto	and_then (this self_t_ &&self_, callable_t_ &&callable_) -> hxremove_cvref_t< decltype(hxforward< callable_t_ >(callable_)(hxdeclval< T & >()))>
bool	equal (const hxref &x_) const
bool	has_value (void) const
hxhash_t	hash (void) const
template<typename self_t_, typename callable_t_>
hxref	or_else (this self_t_ &&self_, callable_t_ &&callable_)
void	reset (void)
void	swap (hxref &x_) noexcept
T &	value (void) const
template<typename self_t_, typename... args_t_>
hxremove_cv_t< T >	value_or (this self_t_ &&self_, args_t_ &&... args_)

Detailed Description

template<typename T>
class hxref< T >

hxref<T> - Holds a reference to a value of type T, or null.

Implements the non-owning pointer std::optional<T&>. A null reference compares equal to hxnil. Assignment rebinds the reference instead of assigning through to the referent, matching pointer semantics. Use hxref<const T> where write through should be prevented.

• T : The referenced value type. Must not be an array, reference or pointer type.

Member Typedef Documentation

value_t

template<typename T>

using hxref< T >::value_t = T&

value_type - Publishes the referenced value type.

Doesn't end with _t because of the standard.

Constructor & Destructor Documentation

hxref() [1/4]

template<typename T>

hxref< T >::hxref ( void )

inline

Constructs a null hxref.

hxref() [2/4]

template<typename T>

hxref< T >::hxref ( hxnil_t )

inline

Constructs a null hxref from hxnil.

• hxnil : The error sentinel.

hxref() [3/4]

template<typename T>

template<typename U_, hxenable_if_t< !hxis_hxref_< hxremove_cvref_t< U_ > >::value &&!hxis_hxexpected_< hxremove_cvref_t< U_ > >::value &&hxbinds_directly< T, U_ >(), bool > = true>

hxref< T >::hxref

(

U_ &

value_

)

Binds a reference to value.

U& must bind to T& without creating a temporary.

• value : The lvalue to reference.

hxref() [4/4]

template<typename T>

template<typename E_>

hxref< T >::hxref

(

hxexpected< T, E_ > &

x_

)

Binds a reference to the value of x.

Accepts an non-null or erroneous hxexpected<T, E>.

• x : The hxexpected whose value to bind.

Member Function Documentation

and_then()

template<typename T>

template<typename self_t_, typename callable_t_>

auto hxref< T >::and_then	(	this self_t_ &&	self_,
		callable_t_ &&	callable_ )->hxremove_cvref_t< decltype(hxforward< callable_t_ >(callable_)(hxdeclval< T & >()))>

Returns the result of calling callable with the referenced value if non-null, otherwise returns hxnil.

Use and_then to return hxptr, hxref or hxexpected.

• callable : The function to call with the referenced value.

equal()

template<typename T>

bool hxref< T >::equal

(

const hxref< T > &

x_

)

const

Returns true if both references are null or both reference equal values.

• x : The hxref to compare against.

has_value()

template<typename T>

bool hxref< T >::has_value ( void ) const

inline

Returns true if the reference is non-null.

hash()

template<typename T>

hxhash_t hxref< T >::hash

(

void

)

const

Returns the hash of the referenced value if non-null, otherwise 31u.

operator bool()

template<typename T>

hxref< T >::operator bool ( void ) const

inlineexplicit

Returns true if the reference is non-null.

operator*()

template<typename T>

T & hxref< T >::operator*

(

void

)

const

Returns a reference to the referenced value.

The reference must be non-null.

operator->()

template<typename T>

T * hxref< T >::operator->

(

void

)

const

Returns a pointer to the referenced value.

The reference must be non-null.

operator=() [1/2]

template<typename T>

hxref & hxref< T >::operator= ( hxnil_t )

inline

Nulls the reference.

The referent is not affected.

• hxnil : The error sentinel.

operator=() [2/2]

template<typename T>

template<typename U_, hxenable_if_t< !hxis_hxref_< hxremove_cvref_t< U_ > >::value &&!hxis_hxexpected_< hxremove_cvref_t< U_ > >::value &&hxbinds_directly< T, U_ >(), bool > = true>

hxref & hxref< T >::operator=

(

U_ &

value_

)

Rebinds the reference to value.

• value : The lvalue to reference.

operator==() [1/3]

template<typename T>

bool hxref< T >::operator== ( const hxref< T > & x_ ) const

inline

Returns true if both references are null or both reference equal values.

• x : Right-hand side reference.

operator==() [2/3]

template<typename T>

bool hxref< T >::operator==

(

const T &

value_

)

const

Returns true if this reference is non-null and its referent equals value.

• value : The value to compare against.

operator==() [3/3]

template<typename T>

bool hxref< T >::operator== ( hxnil_t ) const

inline

Returns true if this reference is null.

• hxnil : The error sentinel.

or_else()

template<typename T>

template<typename self_t_, typename callable_t_>

hxref hxref< T >::or_else	(	this self_t_ &&	self_,
		callable_t_ &&	callable_ )

Returns a copy of this reference if non-null, otherwise returns the result of calling callable.

callable must return an hxref<T>. Implements std::optional::or_else.

• callable : The function to call when null.

reset()

template<typename T>

void hxref< T >::reset ( void )

inline

Nulls the reference. The referent is not affected.

swap()

template<typename T>

void hxref< T >::swap ( hxref< T > & x_ )

noexcept

Exchanges the bound pointers with x.

• x : The hxref to swap with.

value()

template<typename T>

T & hxref< T >::value

(

void

)

const

Returns a reference to the referenced value.

The reference must be non-null.

value_or()

template<typename T>

template<typename self_t_, typename... args_t_>

hxremove_cv_t< T > hxref< T >::value_or	(	this self_t_ &&	self_,
		args_t_ &&...	args_ )

Returns the referenced value if non-null, otherwise returns a T constructed from args.

• args : The arguments used to construct the value when null.

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

• include/hx/hxref.hpp