rust/src/libstd/from_str.rs

// 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.

//! The trait for types that can be created from strings

use option::Option;

/// A trait to abstract the idea of creating a new instance of a type from a
/// string.
pub trait FromStr {
    /// Parses a string `s` to return an optional value of this type. If the
    /// string is ill-formatted, the None is returned.
    fn from_str(s: &str) -> Option<Self>;
}

/// A utility function that just calls FromStr::from_str
pub fn from_str<A: FromStr>(s: &str) -> Option<A> {
    FromStr::from_str(s)
}