option-filter

This crate adds a .filter() method to Option<T>, for older versions of Rust that don't provide it.

Note: Option::filter was added to the standard library in Rust 1.27. Unless you need to support older versions of Rust, you do not need to use this crate.

Usage

To use it, add option-filter to your Cargo.toml:

[dependencies]
option-filter = "1.0"

Then import the extension trait:

extern crate option_filter;
use option_filter::OptionFilterExt;

Now you can filter your Options!

let answer = Some(42);
assert_eq!(answer.filter(|x| *x == 42), Some(42));
assert_eq!(answer.filter(|x| *x == 43), None);