error[E0015]: cannot call non-const operator in constant functions --> $DIR/issue-73976-monomorphic.rs:21:5 | LL | GetTypeId::::VALUE == GetTypeId::::VALUE | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | note: impl defined here, but it is not `const` --> $SRC_DIR/core/src/any.rs:LL:COL = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants help: add `#![feature(effects)]` to the crate attributes to enable | LL + #![feature(effects)] | error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0015`.