warning: unnecessary braces around const expression
  --> $DIR/unused_braces.rs:15:14
   |
LL |     let _: A<{ 7 }>;
   |              ^^^^^ help: remove these braces
   |
note: the lint level is defined here
  --> $DIR/unused_braces.rs:8:9
   |
LL | #![warn(unused_braces)]
   |         ^^^^^^^^^^^^^

warning: 1 warning emitted