Enum Nullable 

pub enum Nullable<T>
where
    T: DataType,
{
    Null,
    Value(T),
}

Nullable data type for the DBMS.

A nullable means that the type can either hold a value of type T or be null. It is a wrapper around another DataType T.

Variants

Null

Value(T)

Implementations

impl<T> Nullable<T>

where T: DataType,

pub fn is_null(&self) -> bool

Checks if the nullable is null.

pub fn is_value(&self) -> bool

Checks if the nullable has a value.

pub fn unwrap(&self) -> &T

Unwraps the nullable to get the inner value.

Panics

Panics if the nullable is null.

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

Returns the inner value as an Option<T>.

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

Returns a mutable reference to the inner value as an Option<T>.

pub fn into_opt(self) -> Option<T>

Converts the nullable into an Option.

Trait Implementations

impl<T> CandidType for Nullable<T>

where T: CandidType + DataType,

fn _ty() -> Type

fn id() -> TypeId

fn idl_serialize<__S>( &self, __serializer: __S, ) -> Result<(), <__S as Serializer>::Error>

where __S: Serializer,

fn ty() -> Type

impl<T> Clone for Nullable<T>

where T: Clone + DataType,

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Debug for Nullable<T>

where T: Debug + DataType,

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

Formats the value using the given formatter.

impl<T> Default for Nullable<T>

where T: DataType,

fn default() -> Nullable<T>

Returns the “default value” for a type.

impl<'de, T> Deserialize<'de> for Nullable<T>

where T: DataType,

fn deserialize<__D>( __deserializer: __D, ) -> Result<Nullable<T>, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T> Display for Nullable<T>

where T: DataType,

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

Formats the value using the given formatter.

impl<T> Encode for Nullable<T>

where T: DataType,

const SIZE: DataSize = DataSize::Dynamic

The size characteristic of the data type.

const ALIGNMENT: u16 = 32u16

The alignment requirement in bytes for the data type.

fn encode(&self) -> Cow<'_, [u8]>

Encodes the data type into a vector of bytes.

fn decode(data: Cow<'_, [u8]>) -> Result<Nullable<T>, MemoryError>

where Nullable<T>: Sized,

Decodes the data type from a slice of bytes.

fn size(&self) -> u16

Returns the size in bytes of the encoded data type.

impl<T> From<Nullable<T>> for Value

where T: DataType,

fn from(nullable: Nullable<T>) -> Value

Converts to this type from the input type.

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

where T: DataType,

fn from(value: Option<T>) -> Nullable<T>

Converts to this type from the input type.

impl<T> Hash for Nullable<T>

where T: Hash + DataType,

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

where __H: Hasher,

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> Ord for Nullable<T>

where T: Ord + DataType,

fn cmp(&self, other: &Nullable<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T> PartialEq for Nullable<T>

where T: PartialEq + DataType,

fn eq(&self, other: &Nullable<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> PartialOrd for Nullable<T>

where T: PartialOrd + DataType,

fn partial_cmp(&self, other: &Nullable<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> Serialize for Nullable<T>

where T: DataType + Serialize,

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl<T> Copy for Nullable<T>

where T: Copy + DataType,

impl<T> DataType for Nullable<T>

where T: DataType,

impl<T> Eq for Nullable<T>

where T: Eq + DataType,

impl<T> StructuralPartialEq for Nullable<T>

where T: DataType,