fcppt::optional::object< T > Class Template Reference

Detailed Description

template<typename T>
class fcppt::optional::object< T >

A class that makes values optional.

This class is a wrapper around std::optional that makes the following changes:

• No operator-> and operator*. This has been replaced get_unsafe.
• No operator bool(). This has been replaced by has_value.
• No assignment from T. Assign an optional instead.

Template Parameters

T	Must be move constructible.

See fcppt.optional for more information.

Public Types
using	value_type = T
	The value type.

Public Member Functions
	object ()
	Constructs an empty optional.
	object (T const &)
	Constructs an optional by copying.
	object (T &&)
	Constructs an optional by moving.
T &	get_unsafe ()
	Returns a reference to the current value.
T const &	get_unsafe () const
	Returns a const reference to the current value.
bool	has_value () const
	Returns whether the optional holds a value.

Member Typedef Documentation

value_type

template<typename T >

using fcppt::optional::object< T >::value_type = T

The value type.

Constructor & Destructor Documentation

object() [1/3]

template<typename T >

fcppt::optional::object< T >::object

(

)

Constructs an empty optional.

Postcondition

has_value() will be false.

object() [2/3]

template<typename T >

fcppt::optional::object< T >::object ( T const &  )

explicit

Constructs an optional by copying.

object() [3/3]

template<typename T >

fcppt::optional::object< T >::object ( T &&  )

explicit

Constructs an optional by moving.

Member Function Documentation

get_unsafe() [1/2]

template<typename T >

T & fcppt::optional::object< T >::get_unsafe

(

)

Returns a reference to the current value.

Warning

The behaviour is undefined if has_value() is false.

get_unsafe() [2/2]

template<typename T >

T const & fcppt::optional::object< T >::get_unsafe

(

)

const

Returns a const reference to the current value.

Warning

The behaviour is undefined if has_value() is false.

has_value()

template<typename T >

bool fcppt::optional::object< T >::has_value

(

)

const

Returns whether the optional holds a value.