Cleanup #1

- Removed notes
- Removed superfluous uses of `where`

src/utils/replace_first.rs

@@ -2,9 +2,12 @@ use std::iter;
 
 /// Iterate over a sequence with the first element the function returns
 /// Some() for updated, but only if there is such an element.
-pub fn replace_first<'a, T, F>(slice: &'a [T], mut f: F)
--> Option<impl Iterator<Item = T> + 'a>
-where T: Clone, F: FnMut(&T) -> Option<T> {
+pub fn replace_first<
+  T: Clone,
+  F: FnMut(&T) -> Option<T>
+>(
+  slice: &[T], mut f: F
+) -> Option<impl Iterator<Item = T> + '_> {
   for i in 0..slice.len() {
     if let Some(new) = f(&slice[i]) {
       let subbed_iter = slice[0..i].iter().cloned()