Struct NullableOption

#[repr(C)]
pub struct NullableOption<T: Nullable>(/* private fields */);

Borsh encodes standard Options with either a 1 or 0 representing the Some or None variants. This means an Optionfor example, is alternately encoded as 33 bytes or 1 byte.NullableOptiontype allows creating a fixed-size genericOptiontype that can be used as anOptionwithout requiring extra space to indicate if the value isSomeorNone. In the Pubkey` example it is now always 32 bytes making it friendly to getProgramAccount calls and creating fixed-size on-chain accounts.

This requires T to implement the Nullable trait so that it defines a NONE value and can indicate if it is Some or None.

Implementations

impl<T: Nullable> NullableOption<T>

pub fn new(value: T) -> Self

pub fn value(&self) -> Option<&T>

pub fn value_mut(&mut self) -> Option<&mut T>

pub fn none() -> Self

Trait Implementations

impl<T: Nullable> BorshDeserialize for NullableOption<T>

fn deserialize_reader<R: Read>(reader: &mut R) -> Result<Self, Error>

fn deserialize(buf: &mut &[u8]) -> Result<Self, Error>

Deserializes this instance from a given slice of bytes. Updates the buffer to point at the remaining bytes.

fn try_from_slice(v: &[u8]) -> Result<Self, Error>

Deserialize this instance from a slice of bytes.

fn try_from_reader<R>(reader: &mut R) -> Result<Self, Error>

where R: Read,

impl<T: Nullable> BorshSerialize for NullableOption<T>

fn serialize<W: Write>(&self, writer: &mut W) -> Result<(), Error>

fn try_to_vec(&self) -> Result<Vec<u8>, Error>

Serialize this instance into a vector of bytes.

impl<T: Clone + Nullable> Clone for NullableOption<T>

fn clone(&self) -> NullableOption<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug + Nullable> Debug for NullableOption<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Nullable> Default for NullableOption<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Nullable> From<Option<T>> for NullableOption<T>

fn from(option: Option<T>) -> Self

Converts to this type from the input type.

impl<T: Hash + Nullable> Hash for NullableOption<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: PartialEq + Nullable> PartialEq for NullableOption<T>

fn eq(&self, other: &NullableOption<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: Copy + Nullable> Copy for NullableOption<T>

impl<T: Eq + Nullable> Eq for NullableOption<T>

impl<T: Nullable> StructuralPartialEq for NullableOption<T>