warning: unnecessary parentheses around `return` value
  --> $DIR/path-lookahead.rs:8:10
   |
LL |   return (<T as ToString>::to_string(&arg));
   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
   |
note: lint level defined here
  --> $DIR/path-lookahead.rs:3:9
   |
LL | #![warn(unused_parens)]
   |         ^^^^^^^^^^^^^