error: conflicting implementations of trait `Trait` for type `for<'a, 'b> fn(&'a &'b u32, &'b &'a u32) -> &'b u32`
  --> $DIR/coherence-fn-implied-bounds.rs:21:1
   |
LL | impl Trait for for<'a, 'b> fn(&'a &'b u32, &'b &'a u32) -> &'b u32 {}
   | ------------------------------------------------------------------ first implementation here
LL |
LL | impl Trait for for<'c> fn(&'c &'c u32, &'c &'c u32) -> &'c u32 {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `for<'a, 'b> fn(&'a &'b u32, &'b &'a u32) -> &'b u32`
   |
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #56105 <https://github.com/rust-lang/rust/issues/56105>
   = note: this behavior recently changed as a result of a bug fix; see rust-lang/rust#56105 for details
note: the lint level is defined here
  --> $DIR/coherence-fn-implied-bounds.rs:15:9
   |
LL | #![deny(coherence_leak_check)]
   |         ^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error