kanzi::FlatOptional< T, sentinel, typename > Class Template Reference

Optional-like lightweight wrapper around type T with no space overhead. More...

#include <kanzi/core/util/flat_optional.hpp>

Public Types
using	ValueType
	Alias for underlying type.

Public Member Functions
KZ_NO_DISCARD optional< T >	createOptional () const noexcept
	Creates a kanzi::optional copy of the stored value.
	FlatOptional () noexcept
	Constructor.
template<typename U , typename = enable_if_t<is_convertible_v<decay_t<U>, T>>>
	FlatOptional (U &&value) noexcept
	Constructor.
KZ_NO_DISCARD bool	hasValue () const noexcept
	Checks if a value is stored.
KZ_NO_DISCARD	operator bool () const noexcept
	Conversion operator to bool.
KZ_NO_DISCARD T &&	operator* () &&noexcept
	Provides access to stored value via rvalue reference.
KZ_NO_DISCARD T &	operator* () &noexcept
	Provides access to stored value via reference.
KZ_NO_DISCARD const T &&	operator* () const &&noexcept
	Provides access to stored value via const rvalue reference.
KZ_NO_DISCARD const T &	operator* () const &noexcept
	Provides access to stored value via const reference.
KZ_NO_DISCARD const T *	operator-> () const noexcept
	Provides access to stored value via const pointer.
KZ_NO_DISCARD T *	operator-> () noexcept
	Provides access to stored value via pointer.
void	reset () noexcept
	Replaces stored value with sentinel value.
template<typename U , typename = enable_if_t<is_convertible_v<decay_t<U>, T>>>
void	reset (U &&newValue) noexcept
	Stores a new value inside.
void	swap (FlatOptional &other)
	Swap function.
KZ_NO_DISCARD optional< T >	toOptional () &&noexcept
	Converts FlatOptional to kanzi::optional.

Static Public Member Functions
static constexpr T	getSentinel () noexcept
	Gets sentinel value that can be used to represent an empty state.

Protected Attributes
T	m_value
	Stored value.

Detailed Description

template<typename T, T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>
class kanzi::FlatOptional< T, sentinel, typename >

Optional-like lightweight wrapper around type T with no space overhead.

Uses sentinel value to represent empty state.

Template Parameters

T	Type of the value.
sentinel	Sentinel value that can be used to represent empty state.

Since

Kanzi 4.0.0

Member Typedef Documentation

ValueType

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

using kanzi::FlatOptional< T, sentinel, typename >::ValueType

Alias for underlying type.

Constructor & Destructor Documentation

FlatOptional() [1/2]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

kanzi::FlatOptional< T, sentinel, typename >::FlatOptional ( )

inlineexplicitnoexcept

Constructor.

Creates FlatOptional with empty state.

FlatOptional() [2/2]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

template<typename U , typename = enable_if_t<is_convertible_v<decay_t<U>, T>>>

kanzi::FlatOptional< T, sentinel, typename >::FlatOptional ( U && value )

inlineexplicitnoexcept

Constructor.

Template Parameters

U	Deduced type for universal reference of T.

Parameters

value

Value to store.

Member Function Documentation

swap()

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

void kanzi::FlatOptional< T, sentinel, typename >::swap ( FlatOptional< T, sentinel, typename > & other )

inline

Swap function.

Parameters

other

Second object to swap with.

operator*() [1/4]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD T & kanzi::FlatOptional< T, sentinel, typename >::operator* ( ) &

inlinenoexcept

Provides access to stored value via reference.

Returns

Reference to stored value.

operator*() [2/4]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD const T & kanzi::FlatOptional< T, sentinel, typename >::operator* ( ) const &

inlinenoexcept

Provides access to stored value via const reference.

Returns

Const reference to stored value.

operator*() [3/4]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD T && kanzi::FlatOptional< T, sentinel, typename >::operator* ( ) &&

inlinenoexcept

Provides access to stored value via rvalue reference.

Returns

Rvalue reference to stored value.

operator*() [4/4]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD const T && kanzi::FlatOptional< T, sentinel, typename >::operator* ( ) const &&

inlinenoexcept

Provides access to stored value via const rvalue reference.

Returns

Const rvalue reference to stored value.

operator->() [1/2]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD T * kanzi::FlatOptional< T, sentinel, typename >::operator-> ( )

inlinenoexcept

Provides access to stored value via pointer.

Returns

Pointer to stored value.

operator->() [2/2]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD const T * kanzi::FlatOptional< T, sentinel, typename >::operator-> ( ) const

inlinenoexcept

Provides access to stored value via const pointer.

Returns

Const pointer to stored value.

operator bool()

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD kanzi::FlatOptional< T, sentinel, typename >::operator bool ( ) const

inlineexplicitnoexcept

Conversion operator to bool.

Returns

If holds a value, true, otherwise false.

hasValue()

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD bool kanzi::FlatOptional< T, sentinel, typename >::hasValue ( ) const

inlinenoexcept

Checks if a value is stored.

Returns

If holds a value, true, otherwise false.

getSentinel()

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

static constexpr T kanzi::FlatOptional< T, sentinel, typename >::getSentinel ( )

inlinestaticconstexprnoexcept

Gets sentinel value that can be used to represent an empty state.

Returns

Sentinel value.

reset() [1/2]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

void kanzi::FlatOptional< T, sentinel, typename >::reset ( )

inlinenoexcept

Replaces stored value with sentinel value.

reset() [2/2]

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

template<typename U , typename = enable_if_t<is_convertible_v<decay_t<U>, T>>>

void kanzi::FlatOptional< T, sentinel, typename >::reset ( U && newValue )

inlinenoexcept

Stores a new value inside.

Template Parameters

U	Deduced type for universal reference of T.

Parameters

newValue

New value to store.

toOptional()

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD optional< T > kanzi::FlatOptional< T, sentinel, typename >::toOptional ( ) &&

inlinenoexcept

Converts FlatOptional to kanzi::optional.

Use by moving the value first:

auto flatOpt = FlatOptional<int, 0>{ 2 };
kanzi::optional<int> kzOpt = kanzi::move(flatOpt).toOptional();

Return values

nullopt

FlatOptional represented an empty value.

Returns

kanzi::optional equivalent.

createOptional()

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

KZ_NO_DISCARD optional< T > kanzi::FlatOptional< T, sentinel, typename >::createOptional ( ) const

inlinenoexcept

Creates a kanzi::optional copy of the stored value.

Return values

nullopt

FlatOptional represented an empty value.

Returns

kanzi::optional equivalent.

Member Data Documentation

m_value

template<typename T , T sentinel, typename = enable_if_t<satisfiesFlatOptional<T>>>

T kanzi::FlatOptional< T, sentinel, typename >::m_value

protected

Stored value.

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

• kanzi/core/util/flat_optional.hpp