rust/src/test/run-pass/match-with-ret-arm.rs
Alex Crichton 0cdde6e5e0 std: Stabilize FromStr and parse
This commits adds an associated type to the `FromStr` trait representing an
error payload for parses which do not succeed. The previous return value,
`Option<Self>` did not allow for this form of payload. After the associated type
was added, the following attributes were applied:

* `FromStr` is now stable
* `FromStr::Err` is now stable
* `FromStr::from_str` is now stable
* `StrExt::parse` is now stable
* `FromStr for bool` is now stable
* `FromStr for $float` is now stable
* `FromStr for $integral` is now stable
* Errors returned from stable `FromStr` implementations are stable
* Errors implement `Display` and `Error` (both impl blocks being `#[stable]`)

Closes #15138
2015-01-30 08:52:44 -08:00

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777 B
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::uint;
pub fn main() {
// sometimes we have had trouble finding
// the right type for f, as we unified
// bot and u32 here
let f = match "1234".parse::<uint>().ok() {
None => return (),
Some(num) => num as u32
};
assert_eq!(f, 1234u32);
println!("{}", f)
}