Crate unsure

unsure.rs - implements a custom Unsure<T> enum which is essentially Option<T> with an additional Reject variant, for handling values that are deemed to be wholly negative rather than undefined.

Uses Haskell variant names, so as to not conflict with Rust’s Option enum, which is defined globally across every Rust program.

It’s sort of like Option<T> with a Result<T, E> twist. Although it’s really just an Option<T> with two None-adjacent variants.

This file is part of unsure-rs.

(c) 2025 Arsalan “Aeri” Kazmi https://aeriavelocity.dev

// It's recommended to use the wildcard import so you don't have to type out
// `unsure::Unsure::` every single time you want to use a variant.
use unsure::Unsure::{self, *};

fn main() {
    let unsure_value: Unsure<i32> = some_function_that_might_fail();

    match unsure_value {
        Just(value) => println!("Value: {}", value),
        Nothing => eprintln!("The function returned nothing"),
        Reject => eprintln!("The function rejected the request"),
    }
}

unsure.rs is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

unsure.rs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with unsure.rs. If not, see https://www.gnu.org/licenses/gpl-3.0.html.

Enums

Unsure

The Unsure type. Used to handle a potential failure where there would otherwise be an Option.