Enum Nullable

pub enum Nullable<T> {
    Valid(T),
    Null,
}

Variants

Valid(T)

Null

Implementations

impl<T> Nullable<T>

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

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

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

pub fn is_valid(&self) -> bool

pub fn is_null(&self) -> bool

pub fn unwrap(self) -> T

Return value if this enum is Valid(value), otherwise panics.

pub fn expect<'a, A>(self, msg: &'a A) -> T

where &'a A: Into<Cow<'a, str>>,

Return value if this enum is Valid(value), otherwise panics with the error message msg.

pub fn valid_or<E>(self, err: E) -> Result<T, E>

Convert to a result, returning err if this enum is Null.

pub fn map<U, F>(self, func: F) -> Nullable<U>

where F: FnOnce(T) -> U,

Maps the T value inside a Nullable<T>::Valid into the U of a Nullable<U>::Valid using the provided func argument, or returns Null if this enum is Null.

pub fn and_then<U, F>(self, func: F) -> Nullable<U>

where F: FnOnce(T) -> Nullable<U>,

Returns Null if this value is Null, or, if this enum is Valid(value), it calls func(value) and returns func’s result. This is very similar to Nullable::map(). However, map() maps the value inside a Valid(value) to another Valid(value), while and_then() can be used to reject a valid value and return null anyway.

Trait Implementations

impl<'fcx, T> ArgAbi<'fcx> for Nullable<T>

where T: ArgAbi<'fcx>,

unsafe fn unbox_arg_unchecked(arg: Arg<'_, 'fcx>) -> Self

Unbox an argument with a matching type.

fn is_virtual_arg() -> bool

“Is this a virtual arg?”

unsafe fn unbox_nullable_arg(arg: Arg<'_, 'fcx>) -> Nullable<Self>

Unbox a nullable arg

impl<T> BoxRet for Nullable<T>

where T: BoxRet,

unsafe fn box_into<'fcx>(self, fcinfo: &mut FcInfo<'fcx>) -> Datum<'fcx>

Safety

impl<T> Clone for Nullable<T>

where T: Clone,

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Debug for Nullable<T>

where T: Debug,

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

Formats the value using the given formatter.

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

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

Converts to this type from the input type.

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

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

Converts to this type from the input type.

impl<T> PartialEq for Nullable<T>

where T: PartialEq,

fn eq(&self, other: &Self) -> 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 + PartialEq,

fn partial_cmp(&self, other: &Self) -> 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> SqlTranslatable for Nullable<T>

where T: SqlTranslatable,

fn argument_sql() -> Result<SqlMapping, ArgumentError>

fn return_sql() -> Result<Returns, ReturnsError>

fn optional() -> bool

fn type_name() -> &'static str

fn variadic() -> bool

fn entity() -> FunctionMetadataTypeEntity

impl<T> Copy for Nullable<T>

where T: Copy,