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#![deny(missing_docs, warnings)]
#![feature(phase, globs)]
pub trait Modifier<F> {
fn modify(self, &mut F);
}
pub trait Set: Sized {
#[inline(always)]
fn set<M: Modifier<Self>>(mut self, modifier: M) -> Self {
modifier.modify(&mut self);
self
}
#[inline(always)]
fn set_mut<M: Modifier<Self>>(&mut self, modifier: M) -> &mut Self {
modifier.modify(self);
self
}
}
mod impls;
#[cfg(test)]
mod test {
#[phase(plugin)] extern crate stainless;
pub use super::*;
pub struct Thing {
x: uint
}
impl Set for Thing {}
pub struct ModifyX(uint);
impl Modifier<Thing> for ModifyX {
fn modify(self, thing: &mut Thing) {
let ModifyX(val) = self;
thing.x = val;
}
}
describe! modifier {
it "should support modifying with set and set_mut" {
let mut thing = Thing { x: 6 };
thing.set_mut(ModifyX(8));
assert_eq!(thing.x, 8);
let thing = thing.set(ModifyX(9));
assert_eq!(thing.x, 9);
}
it "should support tuple chains" {
let thing = Thing { x: 8 }.set((ModifyX(5), ModifyX(112)));
assert_eq!(thing.x, 112);
}
}
}