error: lifetime parameter `'a` only used once
  --> $DIR/one-use-in-fn-argument.rs:8:6
   |
LL | fn a<'a>(x: &'a u32) {
   |      ^^      -- ...is used only here
   |      |
   |      this lifetime...
   |
note: the lint level is defined here
  --> $DIR/one-use-in-fn-argument.rs:1:9
   |
LL | #![deny(single_use_lifetimes)]
   |         ^^^^^^^^^^^^^^^^^^^^
help: elide the single-use lifetime
   |
LL - fn a<'a>(x: &'a u32) {
LL + fn a(x: &u32) {
   | 

error: lifetime parameter `'m` only used once
  --> $DIR/one-use-in-fn-argument.rs:15:11
   |
LL | fn center<'m>(_: Single<'m>) {}
   |           ^^            -- ...is used only here
   |           |
   |           this lifetime...
   |
help: elide the single-use lifetime
   |
LL - fn center<'m>(_: Single<'m>) {}
LL + fn center(_: Single<'_>) {}
   | 

error: lifetime parameter `'y` only used once
  --> $DIR/one-use-in-fn-argument.rs:17:13
   |
LL | fn left<'x, 'y>(foo: Double<'x, 'y>) -> &'x u32 { foo.f }
   |             ^^ this lifetime... -- ...is used only here
   |
help: elide the single-use lifetime
   |
LL - fn left<'x, 'y>(foo: Double<'x, 'y>) -> &'x u32 { foo.f }
LL + fn left<'x>(foo: Double<'x, '_>) -> &'x u32 { foo.f }
   | 

error: lifetime parameter `'x` only used once
  --> $DIR/one-use-in-fn-argument.rs:19:10
   |
LL | fn right<'x, 'y>(foo: Double<'x, 'y>) -> &'y u32 { foo.f }
   |          ^^ this lifetime... -- ...is used only here
   |
help: elide the single-use lifetime
   |
LL - fn right<'x, 'y>(foo: Double<'x, 'y>) -> &'y u32 { foo.f }
LL + fn right<'y>(foo: Double<'_, 'y>) -> &'y u32 { foo.f }
   | 

error: aborting due to 4 previous errors

