hxoptional< T > Class Template Reference

#include <hxoptional.hpp>

Public Types
using	value_type = T

Public Member Functions
	hxoptional (void)
	hxoptional (hxnullopt_t)
	hxoptional (const hxoptional &other_) noexcept
	hxoptional (hxoptional &&other_) noexcept
template<typename U_>
	hxoptional (const hxoptional< U_ > &other_) noexcept
template<typename U_>
	hxoptional (hxoptional< U_ > &&other_) noexcept
template<typename U_ = T, hxenable_if_t< !hxdetail_::hxis_hxoptional_< hxremove_cvref_t< U_ > >::value, bool > = true>
	hxoptional (U_ &&value_) noexcept
	~hxoptional (void)
T &	operator* (void)
const T &	operator* (void) const
T *	operator-> (void)
const T *	operator-> (void) const
	operator bool (void) const
hxoptional &	operator= (const hxoptional &other_) noexcept
hxoptional &	operator= (hxoptional &&other_) noexcept
hxoptional &	operator= (hxnullopt_t)
template<typename U_ = T, hxenable_if_t< !hxdetail_::hxis_hxoptional_< hxremove_cvref_t< U_ > >::value, bool > = true>
hxoptional &	operator= (U_ &&value_) noexcept
template<typename U_>
hxoptional &	operator= (const hxoptional< U_ > &other_) noexcept
template<typename U_>
hxoptional &	operator= (hxoptional< U_ > &&other_) noexcept
bool	operator== (const hxoptional &rhs_) const
bool	operator== (hxnullopt_t) const
bool	operator== (const T &value_) const
template<typename function_t_>
auto	and_then (function_t_ &&callable_) -> hxremove_cvref_t< decltype(hxforward< function_t_ >(callable_)(hxdeclval< T & >()))>
template<typename function_t_>
auto	and_then (function_t_ &&callable_) const -> hxremove_cvref_t< decltype(hxforward< function_t_ >(callable_)(hxdeclval< const T & >()))>
template<typename... args_t_>
T &	emplace (args_t_ &&... args_) noexcept
bool	has_value (void) const
template<typename function_t_>
hxoptional	or_else (function_t_ &&callable_) const
void	reset (void) noexcept
void	swap (hxoptional &other_) noexcept
T &	value (void)
const T &	value (void) const
template<typename U_ = T>
T	value_or (U_ &&default_value_) const

Detailed Description

template<typename T>
class hxoptional< T >

hxoptional<T> - Holds either a value of type T or nothing.

Implements std::optional. See hxref for a std::optional<T&> equivalent. The value is stored in aligned internal storage without dynamic allocation. A disengaged optional compares equal to hxnullopt.

• T : The contained value type. Must not be a reference or pointer type. Use hxref<T> for reference or pointer types.

Member Typedef Documentation

value_type

template<typename T>

using hxoptional< T >::value_type = T

value_type - Publishes the contained value type.

Doesn't end with _t because of the standard.

Constructor & Destructor Documentation

hxoptional() [1/7]

template<typename T>

hxoptional< T >::hxoptional ( void )

inline

Constructs a disengaged hxoptional.

hxoptional() [2/7]

template<typename T>

hxoptional< T >::hxoptional ( hxnullopt_t )

inline

Constructs a disengaged hxoptional from hxnullopt.

• nullopt : The disengaged sentinel.

hxoptional() [3/7]

template<typename T>

hxoptional< T >::hxoptional ( const hxoptional< T > & other_ )

noexcept

Copy constructor.

Copies the engaged state and value from other.

• other : The hxoptional to copy from.

hxoptional() [4/7]

template<typename T>

hxoptional< T >::hxoptional ( hxoptional< T > && other_ )

noexcept

Move constructor.

Moves the engaged state and value from other. other is left disengaged.

• other : The hxoptional to move from.

hxoptional() [5/7]

template<typename T>

template<typename U_>

hxoptional< T >::hxoptional ( const hxoptional< U_ > & other_ )

noexcept

Constructs by copying the engaged state and converting the value of other to T.

U must be convertible to T.

• other : The hxoptional to copy from.

hxoptional() [6/7]

template<typename T>

template<typename U_>

hxoptional< T >::hxoptional ( hxoptional< U_ > && other_ )

noexcept

Constructs by moving the engaged state and converting the value of other to T.

other is left disengaged. U must be convertible to T.

• other : The hxoptional to move from.

hxoptional() [7/7]

template<typename T>

template<typename U_ = T, hxenable_if_t< !hxdetail_::hxis_hxoptional_< hxremove_cvref_t< U_ > >::value, bool > = true>

hxoptional< T >::hxoptional ( U_ && value_ )

noexcept

Constructs an engaged hxoptional by forwarding value into storage.

• value : The value to construct from. Must be convertible to T.

~hxoptional()

template<typename T>

hxoptional< T >::~hxoptional ( void )

inline

Destroys the contained value if engaged.

Member Function Documentation

and_then() [1/2]

template<typename T>

template<typename function_t_>

auto hxoptional< T >::and_then

(

function_t_ &&

callable_

)

->hxremove_cvref_t< decltype(hxforward< function_t_ >(callable_)(hxdeclval< T & >()))>

Returns the result of calling callable with the contained value if engaged, otherwise returns a disengaged optional of the same type.

callable must return an hxoptional.

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

and_then() [2/2]

template<typename T>

template<typename function_t_>

auto hxoptional< T >::and_then

(

function_t_ &&

callable_

)

const->hxremove_cvref_t< decltype(hxforward< function_t_ >(callable_)(hxdeclval< constT & >()))>

Returns the result of calling callable with the contained value if engaged, otherwise returns a disengaged optional of the same type.

callable must return an hxoptional.

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

emplace()

template<typename T>

template<typename... args_t_>

T & hxoptional< T >::emplace ( args_t_ &&... args_ )

noexcept

Constructs the contained value in place from args, destroying any previous value.

• args : Arguments forwarded to the constructor of T.

has_value()

template<typename T>

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

inline

Returns true if the optional contains a value.

operator bool()

template<typename T>

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

inline

Returns true if the optional contains a value.

operator*() [1/2]

template<typename T>

T & hxoptional< T >::operator*

(

void

)

Returns a reference to the contained value.

The optional must be engaged.

operator*() [2/2]

template<typename T>

const T & hxoptional< T >::operator*

(

void

)

const

Returns a const reference to the contained value.

The optional must be engaged.

operator->() [1/2]

template<typename T>

T * hxoptional< T >::operator->

(

void

)

Returns a pointer to the contained value. The optional must be engaged.

operator->() [2/2]

template<typename T>

const T * hxoptional< T >::operator->

(

void

)

const

Returns a const pointer to the contained value.

The optional must be engaged.

operator=() [1/6]

template<typename T>

hxoptional & hxoptional< T >::operator= ( const hxoptional< T > & other_ )

noexcept

Copy assignment.

Copies the engaged state and value from other.

• other : The hxoptional to copy from.

operator=() [2/6]

template<typename T>

template<typename U_>

hxoptional & hxoptional< T >::operator= ( const hxoptional< U_ > & other_ )

noexcept

Copies the engaged state and converts the value of other to T.

U must be convertible to T.

• other : The hxoptional to copy from.

operator=() [3/6]

template<typename T>

hxoptional & hxoptional< T >::operator= ( hxnullopt_t )

inline

Disengages the optional, destroying any contained value.

• nullopt : The disengaged sentinel.

operator=() [4/6]

template<typename T>

hxoptional & hxoptional< T >::operator= ( hxoptional< T > && other_ )

noexcept

Move assignment.

Moves the engaged state and value from other. other is left disengaged.

• other : The hxoptional to move from.

operator=() [5/6]

template<typename T>

template<typename U_>

hxoptional & hxoptional< T >::operator= ( hxoptional< U_ > && other_ )

noexcept

Moves the engaged state and converts the value of other to T.

other is left disengaged. U must be convertible to T.

• other : The hxoptional to move from.

operator=() [6/6]

template<typename T>

template<typename U_ = T, hxenable_if_t< !hxdetail_::hxis_hxoptional_< hxremove_cvref_t< U_ > >::value, bool > = true>

hxoptional & hxoptional< T >::operator= ( U_ && value_ )

noexcept

Assigns value by forwarding, engaging the optional.

• value : The value to assign from. Must be convertible to T.

operator==() [1/3]

template<typename T>

bool hxoptional< T >::operator==

(

const hxoptional< T > &

rhs_

)

const

Returns true if both optionals are disengaged or both are engaged with equal values.

• rhs : Right-hand side optional.

operator==() [2/3]

template<typename T>

bool hxoptional< T >::operator==

(

const T &

value_

)

const

Returns true if this optional is engaged and its value equals value.

• value : The value to compare against.

operator==() [3/3]

template<typename T>

bool hxoptional< T >::operator== ( hxnullopt_t ) const

inline

Returns true if this optional is disengaged.

• nullopt : The disengaged sentinel.

or_else()

template<typename T>

template<typename function_t_>

hxoptional hxoptional< T >::or_else

(

function_t_ &&

callable_

)

const

Returns a copy of this optional if engaged, otherwise returns the result of calling callable.

callable must return an hxoptional<T>.

• callable : The function to call when disengaged.

reset()

template<typename T>

void hxoptional< T >::reset ( void )

noexcept

Destroys the contained value if engaged and leaves the optional disengaged.

swap()

template<typename T>

void hxoptional< T >::swap ( hxoptional< T > & other_ )

noexcept

Exchanges the contents with other.

Both engaged states and values are swapped.

• other : The hxoptional to swap with.

value() [1/2]

template<typename T>

T & hxoptional< T >::value

(

void

)

Returns a reference to the contained value.

The optional must be engaged.

value() [2/2]

template<typename T>

const T & hxoptional< T >::value

(

void

)

const

Returns a const reference to the contained value.

The optional must be engaged.

value_or()

template<typename T>

template<typename U_ = T>

T hxoptional< T >::value_or

(

U_ &&

default_value_

)

const

Returns the contained value if engaged, otherwise returns default_value forwarded and converted to T.

• default_value : The value to return when disengaged.

---

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

• include/hx/hxoptional.hpp