template<typename Type>
class Geo::Optional

Class allowing a value object (integer, string, etc) to be optional, by storing a current value, default value and a boolean to state which is valid.

The template type 'Type' must be default-constructible.

Functions

Name	Description
Default()	Returns the default value.
IsDefaultDefined()	Returns true if the default value has been set.
IsDefined()	Returns true if the value has been set.
Load(Geo::IGeoStream &)	Load this Geo::Optional<Type> from a Geo::IGeoStream.
operator!=(const Optional &)	Inequality operator.
operator=(const Type &)	Assignment operator.
operator==(const Optional &)	Equality operator.
Optional()	Constructor. Defaults to undefined.
Optional(const Type &)	Explicit construction from a value.
Optional(const Optional &)	Copy constructor.
Optional(void *, const Type &)	Constructor that allows you to set a default, but leave value undefined.
Save(Geo::IGeoStream &)	Save this Geo::Optional<Type> to a Geo::IGeoStream.
SetDefault(const Type &)	Set the default value.
Undefine()	Unsets the value, returning it to the default.
UndefineDefault()	Unsets the default value.
Value()	Return the value, if set, otherwise the default.

const Type& Geo::Optional< Type >::Default

public: const Type & Default() const

Returns the default value.

bool Geo::Optional< Type >::IsDefaultDefined

public: bool IsDefaultDefined() const

Returns true if the default value has been set.

bool Geo::Optional< Type >::IsDefined

public: bool IsDefined() const

Returns true if the value has been set.

bool Geo::Optional< Type >::Load

public: bool Load
(
Geo::IGeoStream & stream
)

Load this Geo::Optional<Type> from a Geo::IGeoStream.

Expected the file value to be in little-endian, and restores to native. Does not read/modify the default value.

bool Geo::Optional< Type >::operator!=

public: bool operator!=
(
const Optional & v
) const

Inequality operator.

Optional& Geo::Optional< Type >::operator=

public: Optional & operator=
(
const Type & v
)

Assignment operator.

bool Geo::Optional< Type >::operator==

public: bool operator==
(
const Optional & v
) const

Equality operator.

Geo::Optional< Type >::Optional

public: Optional()

Constructor. Defaults to undefined.

Geo::Optional< Type >::Optional

public: Optional
(
const Type & v
)

Explicit construction from a value.

Geo::Optional< Type >::Optional

public: Optional
(
const Optional & v
)

Copy constructor.

Geo::Optional< Type >::Optional

public: Optional
(
void * ,
const Type & def
)

Constructor that allows you to set a default, but leave value undefined.

bool Geo::Optional< Type >::Save

public: bool Save
(
Geo::IGeoStream & stream
) const

Save this Geo::Optional<Type> to a Geo::IGeoStream.

Writes the file value in little-endian. Does not store the default value.

void Geo::Optional< Type >::SetDefault

public: void SetDefault
(
const Type & val
)

Set the default value.

void Geo::Optional< Type >::Undefine

public: void Undefine()

Unsets the value, returning it to the default.

void Geo::Optional< Type >::UndefineDefault

public: void UndefineDefault()

Unsets the default value.

const Type& Geo::Optional< Type >::Value

public: const Type & Value() const

Return the value, if set, otherwise the default.