Macro flatten

macro_rules! flatten {
    ($opt:expr $(,)? ) => { ... };
}

A const equivalent of Option::flatten

Const stabilization

The equivalent std function was const-stabilized in Rust 1.83.0.

Example

use konst::option;

const ARR: &[Option<u32>] = &[
    option::flatten!(Some(Some(8))),
    option::flatten!(None),
];

assert_eq!(ARR, &[Some(8), None]);