error: generic parameters may not be used in enum discriminant values --> $DIR/issue-70453-generics-in-discr-ice.rs:10:32 | LL | Some = std::mem::size_of::(), | ^ cannot perform const operation using `T` | = note: type parameters may not be used in enum discriminant values error[E0392]: parameter `T` is never used --> $DIR/issue-70453-generics-in-discr-ice.rs:7:20 | LL | enum MyWeirdOption { | ^ unused parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` = help: if you intended `T` to be a const parameter, use `const T: usize` instead error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0392`.