warning: function is never used: `gen`
  --> $DIR/issue-49376.rs:18:1
   |
LL | fn gen() -> impl PartialOrd + PartialEq + Debug { }
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: #[warn(dead_code)] on by default

warning: struct is never constructed: `Bar`
  --> $DIR/issue-49376.rs:20:1
   |
LL | struct Bar {}
   | ^^^^^^^^^^

warning: function is never used: `foo`
  --> $DIR/issue-49376.rs:24:1
   |
LL | fn foo() -> impl Foo {
   | ^^^^^^^^^^^^^^^^^^^^

warning: function is never used: `test_impl_ops`
  --> $DIR/issue-49376.rs:28:1
   |
LL | fn test_impl_ops() -> impl Add + Sub + Mul + Div { 1 }
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

warning: function is never used: `test_impl_assign_ops`
  --> $DIR/issue-49376.rs:29:1
   |
LL | fn test_impl_assign_ops() -> impl AddAssign + SubAssign + MulAssign + DivAssign { 1 }
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^