error[E0261]: use of undeclared lifetime name `'foo` --> $DIR/regions-in-enums.rs:13:9 | LL | enum No0 { | - help: consider introducing lifetime `'foo` here: `<'foo>` LL | X5(&'foo usize) | ^^^^ undeclared lifetime error[E0261]: use of undeclared lifetime name `'a` --> $DIR/regions-in-enums.rs:17:9 | LL | enum No1 { | - help: consider introducing lifetime `'a` here: `<'a>` LL | X6(&'a usize) | ^^ undeclared lifetime error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0261`.