Replace trim_{left,right} with trim_{start,end} and co. (using Rerast)

util/rewrite_rules.rs

@@ -0,0 +1,18 @@
+//! Rules to update the codebase using Rerast
+
+/// Converts try!() to ?
+fn try_to_question_mark<T, E, X: From<E>>(r: Result<T, E>) -> Result<T, X> {
+    replace!(try!(r) => r?);
+    unreachable!()
+}
+
+fn trim_left_to_start(s: &str) {
+    replace!(s.trim_left() => s.trim_start());
+    replace!(s.trim_right() => s.trim_end());
+}
+
+fn trim_left_matches_to_start<P: FnMut(char) -> bool>(s: &str, inner: P) {
+    replace!(s.trim_left_matches(inner) => s.trim_start_matches(inner));
+    replace!(s.trim_right_matches(inner) => s.trim_end_matches(inner));
+}
+