matador::optional< T > Class Template Reference

#include <optional.hpp>

Public Types
typedef T	value_type

Public Member Functions
	optional ()=default
	optional (detail::nullopt_t)
	optional (const T &value)
template<class U >
	optional (const optional< U > &x)
optional &	operator= (detail::nullopt_t)
template<class U >
optional &	operator= (const optional< U > &x)
const value_type *	operator-> () const
value_type *	operator-> ()
const value_type &	operator* () const
value_type &	operator* ()
	operator bool () const
const value_type &	value () const
value_type &	value ()
template<class U >
value_type	value_or (U const &v) const
bool	has_value () const
void	reset ()

Detailed Description

template<typename T>
class matador::optional< T >

The optional class provides an object holding a value of type T or not. The value is optional.

Template Parameters

T	Type of the hold optional value

Member Typedef Documentation

value_type

template<typename T >

typedef T matador::optional< T >::value_type

Shortcut to the value type

Constructor & Destructor Documentation

optional() [1/4]

template<typename T >

matador::optional< T >::optional ( )

default

Default constructor

optional() [2/4]

template<typename T >

matador::optional< T >::optional ( detail::nullopt_t  )

inline

Initializes the optional with a null type.

optional() [3/4]

template<typename T >

matador::optional< T >::optional ( const T &  value )

inline

Initializes a new optional with the given value.

Parameters

value

Value of optional

optional() [4/4]

template<typename T >

template<class U >

matador::optional< T >::optional ( const optional< U > &  x )

inline

Copies given optional value x of type U to new optional value of type T. A value of type U must be convertible to type T.

Template Parameters

U	Type of other optional

Parameters

x	Other optional value

Member Function Documentation

has_value()

template<typename T >

bool matador::optional< T >::has_value ( ) const

inline

Returns true if value is set.

Returns

True if value is set

operator bool()

template<typename T >

matador::optional< T >::operator bool ( ) const

inlineexplicit

Boolean operator returns true if optional has a value

Returns

True if valueis available

operator*() [1/2]

template<typename T >

value_type & matador::optional< T >::operator* ( )

inline

Access the underlying value as reference. The value is checked on validity with assert

Returns

The value as reference

operator*() [2/2]

template<typename T >

const value_type & matador::optional< T >::operator* ( ) const

inline

Access the underlying value as reference. The value is checked on validity with assert

Returns

The value as reference

operator->() [1/2]

template<typename T >

value_type * matador::optional< T >::operator-> ( )

inline

Access the underlying value as pointer. The value is checked on validity with assert

Returns

The value as pointer

operator->() [2/2]

template<typename T >

const value_type * matador::optional< T >::operator-> ( ) const

inline

Access the underlying value as pointer. The value is checked on validity with assert

Returns

The value as pointer

operator=() [1/2]

template<typename T >

template<class U >

optional & matador::optional< T >::operator= ( const optional< U > &  x )

inline

Assigns an other optional of type U to this optional. Type U must be convertible to type T.

Template Parameters

U	Type of other optional

Parameters

x	Other optional to be assigned

Returns

The assigned optional

operator=() [2/2]

template<typename T >

optional & matador::optional< T >::operator= ( detail::nullopt_t  )

inline

Assigns a null optional value to this optional. Optional will be set to nullopt.

Returns

The assigned optional

reset()

template<typename T >

void matador::optional< T >::reset ( )

inline

Resets optional to empty (no value set)

value() [1/2]

template<typename T >

value_type & matador::optional< T >::value ( )

inline

Returns a reference to the value. If value isn't available a bad_optional_exception is thrown

Exceptions

bad_optional_exception

If not available

Returns

Reference to the value

value() [2/2]

template<typename T >

const value_type & matador::optional< T >::value ( ) const

inline

Returns a const reference to the value. If value isn't available a bad_optional_exception is thrown

Exceptions

bad_optional_exception

If not available

Returns

Const reference to the value

value_or()

template<typename T >

template<class U >

value_type matador::optional< T >::value_or ( U const &  v ) const

inline

Return a copy of the value or in case value is not set return the given value

This default value is of type U and must be convertible to type T.

Template Parameters

U	Type of default value

Parameters

v	Default value if optional value is not set

Returns

Optional value or default value

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

• matador/utils/optional.hpp