error[E0015]: cannot call non-const fn `::plus` in constant functions --> $DIR/call-const-trait-method-pass.rs:36:7 | LL | a.plus(b) | ^^^^^^^ | = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants error[E0015]: cannot call non-const operator in constants --> $DIR/call-const-trait-method-pass.rs:39:22 | LL | const ADD_INT: Int = Int(1i32) + Int(2i32); | ^^^^^^^^^^^^^^^^^^^^^ | note: impl defined here, but it is not `const` --> $DIR/call-const-trait-method-pass.rs:7:1 | LL | impl const std::ops::Add for Int { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = note: calls in constants are limited to constant functions, tuple structs and tuple variants error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0015`.