error: generic parameters may not be used in const operations --> $DIR/issue-67375.rs:7:25 | LL | inner: [(); { [|_: &T| {}; 0].len() }], | ^ cannot perform const operation using `T` | = note: type parameters may not be used in const expressions = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions error[E0392]: parameter `T` is never used --> $DIR/issue-67375.rs:5:12 | LL | struct Bug { | ^ 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`.