openethereum/util/src/misc.rs

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2016-01-14 21:24:16 +01:00
use common::*;
#[derive(Debug,Clone,PartialEq,Eq)]
/// Diff type for specifying a change (or not).
pub enum Diff<T> where T: Eq {
Same,
Born(T),
Changed(T, T),
Died(T),
}
impl<T> Diff<T> where T: Eq {
/// Construct new object with given `pre` and `post`.
pub fn new(pre: T, post: T) -> Self { if pre == post { Diff::Same } else { Diff::Changed(pre, post) } }
/// Get the before value, if there is one.
pub fn pre(&self) -> Option<&T> { match self { &Diff::Died(ref x) | &Diff::Changed(ref x, _) => Some(x), _ => None } }
/// Get the after value, if there is one.
pub fn post(&self) -> Option<&T> { match self { &Diff::Born(ref x) | &Diff::Changed(_, ref x) => Some(x), _ => None } }
/// Determine whether there was a change or not.
pub fn is_same(&self) -> bool { match self { &Diff::Same => true, _ => false }}
}
#[derive(PartialEq,Eq,Clone,Copy)]
/// Boolean type for clean/dirty status.
pub enum Filth {
Clean,
Dirty,
}