error: generic parameters may not be used in const operations --> $DIR/issue-64173-unused-lifetimes.rs:16:23 | LL | beta: [(); foo::<&'a ()>()], | ^^ cannot perform const operation using `'a` | = note: lifetime parameters may not be used in const expressions = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions error: generic `Self` types are currently not permitted in anonymous constants --> $DIR/issue-64173-unused-lifetimes.rs:4:28 | LL | array: [(); size_of::<&Self>()], | ^^^^ error[E0392]: parameter `'s` is never used --> $DIR/issue-64173-unused-lifetimes.rs:3:12 | LL | struct Foo<'s> { | ^^ unused parameter | = help: consider removing `'s`, referring to it in a field, or using a marker such as `PhantomData` error[E0392]: parameter `'a` is never used --> $DIR/issue-64173-unused-lifetimes.rs:15:12 | LL | struct Bar<'a> { | ^^ unused parameter | = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData` error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0392`.