Trait OptionExt

pub trait OptionExt<T> {
    // Required methods
    fn combine<U>(self, other: Option<U>) -> Option<(T, U)>;
    fn combine_with<U, F, R>(self, other: Option<U>, f: F) -> Option<R>
       where F: FnOnce(T, U) -> R;
}

Extension trait with useful methods for std::option::Option.

Required Methods

fn combine<U>(self, other: Option<U>) -> Option<(T, U)>

Combines self and another Option.

If self is Some(s) and other is Some(o), this method returns Some((s, o)). Otherwise, None is returned.

Note: std::Option already provides a zip method which serves exact same purpose, but currently it’s unstable. Once it’s stabilized, this method will be marked as deprecated with a prompt to use the stanard method instead.

Examples

use stdext::prelude::*;

let x = Some(1);
let y = Some("hi");
let z = None::<u8>;

assert_eq!(x.combine(y), Some((1, "hi")));
assert_eq!(x.combine(z), None);

fn combine_with<U, F, R>(self, other: Option<U>, f: F) -> Option<R>

where F: FnOnce(T, U) -> R,

Combines self and another Option with function f.

If self is Some(s) and other is Some(o), this method returns Some(f(s, o)). Otherwise, None is returned.

Note: std::Option already provides a zip_with method which serves exact same purpose, but currently it’s unstable. Once it’s stabilized, this method will be marked as deprecated with a prompt to use the stanard method instead.

Examples

use stdext::prelude::*;

#[derive(Debug, PartialEq)]
struct Point {
    x: f64,
    y: f64,
}

impl Point {
    fn new(x: f64, y: f64) -> Self {
        Self { x, y }
    }
}

let x = Some(17.5);
let y = Some(42.7);

assert_eq!(x.combine_with(y, Point::new), Some(Point { x: 17.5, y: 42.7 }));
assert_eq!(x.combine_with(None, Point::new), None);

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<T> OptionExt<T> for Option<T>

fn combine<U>(self, other: Option<U>) -> Option<(T, U)>

fn combine_with<U, F, R>(self, other: Option<U>, f: F) -> Option<R>

where F: FnOnce(T, U) -> R,

Implementors