error[E0015]: cannot call non-const operator in constant functions
  --> $DIR/issue-90870.rs:8:5
   |
LL |     a == b
   |     ^^^^^^
   |
   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider dereferencing here
   |
LL |     *a == *b
   |     +     +

error[E0015]: cannot call non-const operator in constant functions
  --> $DIR/issue-90870.rs:14:5
   |
LL |     a == b
   |     ^^^^^^
   |
   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider dereferencing here
   |
LL |     ****a == ****b
   |     ++++     ++++

error[E0015]: cannot call non-const operator in constant functions
  --> $DIR/issue-90870.rs:21:12
   |
LL |         if l == r {
   |            ^^^^^^
   |
   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider dereferencing here
   |
LL |         if *l == *r {
   |            +     +

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0015`.