1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 #![feature(unboxed_closures, std_misc)]
13 use std::thunk::Thunk;
15 pub trait Promisable: Send + Sync {}
16 impl<T: Send + Sync> Promisable for T {}
17 pub fn propagate<'a, T, E, F, G>(action: F) -> Thunk<'a,Result<T, E>, Result<T, E>>
19 T: Promisable + Clone + 'a,
20 E: Promisable + Clone + 'a,
21 F: FnOnce(&T) -> Result<T, E> + Send + 'a,
22 G: FnOnce(Result<T, E>) -> Result<T, E> + 'a {
23 Thunk::with_arg(move |result: Result<T, E>| {
25 Ok(ref t) => action(t),
26 Err(ref e) => Err(e.clone()),