Merge pull request #21 from cuviper/flatten-either

Flatten the implementation of Either::either

src/lib.rs

@@ -290,7 +290,10 @@ impl<L, R> Either<L, R> {
       where F: FnOnce(L) -> T,
             G: FnOnce(R) -> T
     {
-        self.either_with((), move |(), x| f(x), move |(), x| g(x))
+        match self {
+            Left(l) => f(l),
+            Right(r) => g(r),
+        }
     }
 
     /// Like `either`, but provide some context to whichever of the