tryx

tryx is an experimental nightly Rust library for outcome types that work with the ? operator beyond Result and Option.

It currently includes:

• Cancel<T> for cancellation-aware control flow
• Checked<Finite> for checked floating-point operations
• Parsing<'a, T> for parser-style outcomes with diagnostics
• Stage<S, T, P> for staged computations that retain partial state
• #[derive(Outcome)] for simple custom outcome enums

tryx requires nightly Rust and try_trait_v2. The workspace pins nightly-2026-03-28.

Example

#![feature(try_trait_v2)]

use tryx::cancel::{Cancel, CancelToken};

fn work(token: &CancelToken) -> Cancel<u32> {
    token.check()?;
    Cancel::ok(42)
}

let (token, handle) = CancelToken::new();
assert_eq!(work(&token), Cancel::Done(42));

handle.cancel();
assert_eq!(work(&token), Cancel::Cancelled);

Docs

Build the book and API docs locally:

mdbook build docs
cargo doc --workspace --all-features --no-deps

Run the examples:

cargo run -p tryx --example cancel_basic --features cancel
cargo run -p tryx --example quadratic --features checked
cargo run -p tryx --example kv_parser --features parsing
cargo run -p tryx --example etl_pipeline --features stage