Macro matches2::option_match

macro_rules! option_match {
    ($expression:expr, $($pattern:pat)|* $(if $ifguard:expr)? => $result:expr) => { ... };
}

Returns Option::Some if the pattern matches with the given value, or Option::None otherwise

This macro is especially useful with Iterator::filter_map.

Syntax: option_match!( expression , pattern => result )

Examples

#[macro_use]
extern crate matches2;

enum Foo {
    A(i32),
    B(f64),
}

fn main() {
    let data = [Foo::A(1), Foo::B(2.0), Foo::A(3), Foo::B(4.0), Foo::A(5)];
    let vec = data.iter()
        .filter_map(|foo| option_match!(foo, &Foo::A(i) if i <= 3 => i))
        .collect::<Vec<i32>>();
    assert_eq!(&vec[..], &[1, 3]);
}