option-ext

Introduction

This crate extends Option with additional methods, currently:

• contains
• map_or2 (as a replacement for map_or)
• map_or_else2 (as a replacement for map_or_else)

Its sister crate is result-ext, which extends Result.

Requirements

Rust 1.0 or newer.

Usage

Dependency

Add the library as a dependency to your project by inserting

option-ext = "0.2.0"

into the [dependencies] section of your Cargo.toml file.

Example

use option_ext::OptionExt;

fn example_contains() {
    let x: Option<u32> = Some(2);
    assert_eq!(x.contains(&2), true);

    let x: Option<u32> = Some(3);
    assert_eq!(x.contains(&2), false);

    let x: Option<u32> = None;
    assert_eq!(x.contains(&2), false);
}

fn example_map_or2() {
    let x = Some("bar");
    assert_eq!(x.map_or2(|v| v.len(), 42), 3);

    let x: Option<&str> = None;
    assert_eq!(x.map_or2(|v| v.len(), 42), 42);
}

fn example_map_or_else2() {
    let k = 23;
    
    let x = Some("bar");
    assert_eq!(x.map_or_else2(|v| v.len(), || 2 * k), 3);
    
    let x: Option<&str> = None;
    assert_eq!(x.map_or_else2(|v| v.len(), || 2 * k), 46);
}