Fix compilation

See rust-lang/rust#62495

src/lib.rs

@@ -1,5 +1,3 @@
-#![type_length_limit="1814752"]
-
 /// Content-preserving image resizing
 ///
 /// See: [resize]

src/pos.rs

@@ -14,23 +14,21 @@ impl Pos {
  let Pos(x, y) = self;
  once(y + 1)
  .filter(move |&y| y < height)
- .flat_map(move |y| once(x.checked_sub(1))
- .flatten()
- .chain(once(x))
- .chain(once(x + 1)
- .filter(move |&x| x < width)
- )
- .map(move |x| Pos(x, y)))
+ .flat_map(move |y|
+ x.checked_sub(1).into_iter()
+  .chain(once(x))
+  .chain(once(x + 1)
+  .filter(move |&x| x < width)
+  )
+  .map(move |x| Pos(x, y)))
  }
 
  pub fn predecessors(self, size: Pos)
  -> impl Iterator<Item=Pos> {
  let Pos(x, y) = self;
- once(y)
- .flat_map(|y| y.checked_sub(1))
+ y.checked_sub(1).into_iter()
  .flat_map(move |y|
- once(x.checked_sub(1))
- .flatten()
+ x.checked_sub(1).into_iter()
  .chain(once(x))
  .chain(once(x + 1)
  .filter(move |&x| x < size.0)