Struct emf_core_base_rs_ffi::collections::Optional

#[repr(C)]
pub struct Optional<T> where
    T: Copy + Sized,  { /* fields omitted */ }

A type containing an optional value.

Implementations

impl<T> Optional<T> where
    T: Copy + Sized, 

pub fn some(val: T) -> Self

Creates a new Optional<T> containing the value.

pub fn none() -> Self

Creates an empty Optional<T>.

pub fn is_some(&self) -> bool

Returns true if the optional contains a value.

pub fn is_none(&self) -> bool

Returns true if the optional is empty.

pub fn as_ref(&self) -> Optional<&T>

Maps the Optional<T> to Optional<&T>.

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

Maps the Optional<T> to Option<T>.

pub fn expect(self, msg: &str) -> T

Returns the contained value.

Panics

Panics if no value is contained with a custom panic message provided by msg.

pub fn unwrap(self) -> T

Returns the contained value.

Panics

Panics if no value is contained.

pub fn unwrap_or(self, default: T) -> T

Returns the contained value or a default.

pub fn unwrap_or_else<F>(self, f: F) -> T where
    F: FnOnce() -> T, 

Returns the contained value or computes it from a closure.

pub fn map<U, F>(self, f: F) -> Optional<U> where
    U: Copy + Sized,
    F: FnOnce(T) -> U, 

Maps an Optional<T> to Optional<U> by applying a function to the contained value.

pub fn map_or<U, F>(self, default: U, f: F) -> U where
    F: FnOnce(T) -> U, 

Returns the application of the closure to the contained value or a default value.

pub fn map_or_else<U, D, F>(self, default: D, f: F) -> U where
    D: FnOnce() -> U,
    F: FnOnce(T) -> U, 

Applies a function to the contained value (if any), or computes a default (if not).

pub fn ok_or<E>(self, err: E) -> Result<T, E> where
    E: Copy + Sized, 

Transforms the Optional<T> into a Result<T, E>.

pub fn ok_or_else<E, F>(self, f: F) -> Result<T, E> where
    E: Copy + Sized,
    F: FnOnce() -> E, 

Transforms the Optional<T> into a Result<T, E> by mapping the contained value or computing an error value from a closure.

Trait Implementations

impl<T: Clone> Clone for Optional<T> where
    T: Copy + Sized, 

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Copy> Copy for Optional<T> where
    T: Copy + Sized, 

impl<T> Debug for Optional<T> where
    T: Copy + Sized + Debug, 

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

Formats the value using the given formatter.

impl<T> Default for Optional<T> where
    T: Copy + Sized, 

fn default() -> Self

Returns the “default value” for a type.

impl<T> Eq for Optional<T> where
    T: Copy + Sized + PartialEq + Eq, 

impl<T> From<Option<T>> for Optional<T> where
    T: Copy + Sized, 

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

Performs the conversion.

impl<T> PartialEq<Optional<T>> for Optional<T> where
    T: Copy + Sized + PartialEq, 

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use]

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

This method tests for !=.