error[E0277]: can't compare `T` with `T` in const contexts
  --> $DIR/call-generic-method-fail.rs:5:5
   |
LL |     *t == *t
   |     ^^^^^^^^ no implementation for `T == T`
   |
note: the trait `PartialEq` is implemented for `T`, but that implementation is not `const`
  --> $DIR/call-generic-method-fail.rs:5:5
   |
LL |     *t == *t
   |     ^^^^^^^^

error[E0015]: cannot call non-const operator in constant functions
  --> $DIR/call-generic-method-fail.rs:5:5
   |
LL |     *t == *t
   |     ^^^^^^^^
   |
   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider further restricting this bound
   |
LL | pub const fn equals_self<T: PartialEq + ~const std::cmp::PartialEq>(t: &T) -> bool {
   |                                       ++++++++++++++++++++++++++++

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0015, E0277.
For more information about an error, try `rustc --explain E0015`.