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

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.