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 This has been replaced by has_value.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	The type to make optional, which must be CopyConstructible or Movable, Assignable or MoveAssignable and complete. It therefore must also not be const.

See fcppt.optional for more information.

Public Types
using	value_type = T
	The value type. More...

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

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.