A simple optional type. More...

#include <juce_Optional.h>

Public Member Functions
	Optional ()
	Optional (Nullopt) noexcept
template<typename U = Value, typename = std::enable_if_t<std::is_constructible<Value, U&&>::value && ! std::is_same<std::decay_t<U>, Optional>::value>>
	Optional (U &&value) noexcept(noexcept(Value(std::forward< U >(value))))
	Optional (Optional &&other) noexcept(noexcept(std::declval< Optional >().constructFrom(other)))
	Optional (const Optional &other)
template<typename Other, typename = OptionalMoveConstructorEnabled<Value, Other>>
	Optional (Optional< Other > &&other) noexcept(noexcept(std::declval< Optional >().constructFrom(other)))
template<typename Other, typename = OptionalCopyConstructorEnabled<Value, Other>>
	Optional (const Optional< Other > &other)
Optional &	operator= (Nullopt) noexcept
template<typename U = Value, typename = std::enable_if_t<std::is_nothrow_move_constructible<U>::value && std::is_nothrow_move_assignable<U>::value>>
Optional &	operator= (Optional &&other) noexcept(noexcept(std::declval< Optional >().assign(std::declval< Optional & >())))
template<typename U = Value, typename = std::enable_if_t<! std::is_same<std::decay_t<U>, Optional>::value && std::is_constructible<Value, U>::value && std::is_assignable<Value&, U>::value && (! std::is_scalar<Value>::value \|\| ! std::is_same<std::decay_t<U>, Value>::value)>>
Optional &	operator= (U &&value)
Optional &	operator= (const Optional &other)
	Maintains the strong exception safety guarantee.
template<typename Other, typename = OptionalMoveAssignmentEnabled<Value, Other>>
Optional &	operator= (Optional< Other > &&other) noexcept(noexcept(std::declval< Optional >().assign(other)))
template<typename Other, typename = OptionalCopyAssignmentEnabled<Value, Other>>
Optional &	operator= (const Optional< Other > &other)
	Maintains the strong exception safety guarantee.
	~Optional () noexcept
Value *	operator-> () noexcept
const Value *	operator-> () const noexcept
Value &	operator* () noexcept
const Value &	operator* () const noexcept
	operator bool () const noexcept
bool	hasValue () const noexcept
void	reset ()
template<typename U>
Value	orFallback (U &&fallback) const
	Like std::optional::value_or.
template<typename... Args>
Value &	emplace (Args &&... args)
void	swap (Optional &other) noexcept(std::is_nothrow_move_constructible< Value >::value &&detail::adlSwap::isNothrowSwappable< Value >)

Detailed Description

template<typename Value>
class Optional< Value >

A simple optional type.

Has similar (not necessarily identical!) semantics to std::optional.

This is intended to stand-in for std::optional while JUCE's minimum supported language standard is lower than C++17. When the minimum language standard moves to C++17, this class will probably be deprecated, in much the same way that juce::ScopedPointer was deprecated in favour of std::unique_ptr after C++11.

This isn't really intended to be used by JUCE clients. Instead, it's to be used internally in JUCE code, with an API close-enough to std::optional that the types can be swapped with fairly minor disruption at some point in the future, but without breaking any public APIs.

Constructor & Destructor Documentation

◆ Optional() [1/7]

template<typename Value>

Optional< Value >::Optional ( )

References placeholder.

Referenced by operator=(), operator=(), operator=(), operator=(), operator=(), operator=(), Optional(), Optional(), Optional(), Optional(), and swap().

◆ Optional() [2/7]

template<typename Value>

Optional< Value >::Optional ( Nullopt )

noexcept

References placeholder.

◆ Optional() [3/7]

template<typename Value>

template<typename U = Value, typename = std::enable_if_t<std::is_constructible<Value, U&&>::value && ! std::is_same<std::decay_t, Optional>::value>>

Optional< Value >::Optional ( U && value )

noexcept

References storage.

◆ Optional() [4/7]

template<typename Value>

Optional< Value >::Optional ( Optional< Value > && other )

noexcept

References Optional(), and placeholder.

◆ Optional() [5/7]

template<typename Value>

Optional< Value >::Optional ( const Optional< Value > & other )

References Optional(), placeholder, and storage.

◆ Optional() [6/7]

template<typename Value>

template<typename Other, typename = OptionalMoveConstructorEnabled<Value, Other>>

Optional< Value >::Optional ( Optional< Other > && other )

noexcept

References Optional(), and placeholder.

◆ Optional() [7/7]

template<typename Value>

template<typename Other, typename = OptionalCopyConstructorEnabled<Value, Other>>

Optional< Value >::Optional ( const Optional< Other > & other )

References hasValue(), Optional(), placeholder, and storage.

◆ ~Optional()

template<typename Value>

Optional< Value >::~Optional ( )

noexcept

References reset().

Member Function Documentation

◆ operator=() [1/6]

template<typename Value>

Optional & Optional< Value >::operator= ( Nullopt )

noexcept

References Optional(), and reset().

◆ operator=() [2/6]

template<typename Value>

template<typename U = Value, typename = std::enable_if_t<std::is_nothrow_move_constructible::value && std::is_nothrow_move_assignable::value>>

Optional & Optional< Value >::operator= ( Optional< Value > && other )

noexcept

References Optional().

◆ operator=() [3/6]

template<typename Value>

template<typename U = Value, typename = std::enable_if_t<! std::is_same<std::decay_t, Optional>::value && std::is_constructible<Value, U>::value && std::is_assignable<Value&, U>::value && (! std::is_scalar<Value>::value || ! std::is_same<std::decay_t, Value>::value)>>

Optional & Optional< Value >::operator= ( U && value )

References Optional(), and storage.

◆ operator=() [4/6]

template<typename Value>

Optional & Optional< Value >::operator= ( const Optional< Value > & other )

Maintains the strong exception safety guarantee.

References Optional().

◆ operator=() [5/6]

template<typename Value>

template<typename Other, typename = OptionalMoveAssignmentEnabled<Value, Other>>

Optional & Optional< Value >::operator= ( Optional< Other > && other )

noexcept

References Optional().

◆ operator=() [6/6]

template<typename Value>

template<typename Other, typename = OptionalCopyAssignmentEnabled<Value, Other>>

Optional & Optional< Value >::operator= ( const Optional< Other > & other )

Maintains the strong exception safety guarantee.

References Optional().

◆ operator->() [1/2]

template<typename Value>

Value * Optional< Value >::operator-> ( )

noexcept

References storage.

Referenced by operator*(), and operator*().

◆ operator->() [2/2]

template<typename Value>

const Value * Optional< Value >::operator-> ( ) const

noexcept

References storage.

◆ operator*() [1/2]

template<typename Value>

Value & Optional< Value >::operator* ( )

noexcept

References operator->().

◆ operator*() [2/2]

template<typename Value>

const Value & Optional< Value >::operator* ( ) const

noexcept

References operator->().

◆ operator bool()

template<typename Value>

Optional< Value >::operator bool ( ) const

explicitnoexcept

◆ hasValue()

template<typename Value>

bool Optional< Value >::hasValue ( ) const

noexcept

Referenced by operator!=(), operator!=(), operator!=(), operator<(), operator<(), operator<(), operator<=(), operator<=(), operator<=(), operator==(), operator==(), operator==(), operator>(), operator>(), operator>(), operator>=(), operator>=(), operator>=(), Optional(), and swap().

◆ reset()

template<typename Value>

void Optional< Value >::reset ( )

References operator*().

Referenced by emplace(), operator=(), and ~Optional().

◆ orFallback()

template<typename Value>

template<typename U>

Value Optional< Value >::orFallback ( U && fallback ) const

Like std::optional::value_or.

◆ emplace()

template<typename Value>

template<typename... Args>

Value & Optional< Value >::emplace ( Args &&... args )

References reset(), and storage.

◆ swap()

template<typename Value>

void Optional< Value >::swap ( Optional< Value > & other )

noexcept

References hasValue(), detail::adlSwap::isNothrowSwappable, Optional(), and swap().

Referenced by swap().

Member Data Documentation

◆ placeholder

template<typename Value>

char Optional< Value >::placeholder

Referenced by Optional(), Optional(), Optional(), Optional(), Optional(), and Optional().

◆ storage

template<typename Value>

Value Optional< Value >::storage

Referenced by emplace(), operator->(), operator->(), operator=(), Optional(), Optional(), and Optional().

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

juce_Optional.h

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Optional() [1/7]

◆ Optional() [2/7]

◆ Optional() [3/7]

◆ Optional() [4/7]

◆ Optional() [5/7]

◆ Optional() [6/7]

◆ Optional() [7/7]

◆ ~Optional()

Member Function Documentation

◆ operator=() [1/6]

◆ operator=() [2/6]

◆ operator=() [3/6]

◆ operator=() [4/6]

◆ operator=() [5/6]

◆ operator=() [6/6]

◆ operator->() [1/2]

◆ operator->() [2/2]

◆ operator*() [1/2]

◆ operator*() [2/2]

◆ operator bool()

◆ hasValue()

◆ reset()

◆ orFallback()

◆ emplace()

◆ swap()

Member Data Documentation

◆ placeholder

◆ storage