error: expected one of `,` or `>`, found `;` --> $DIR/lifetime-semicolon.rs:7:31 | LL | fn foo<'a, 'b>(_x: &mut Foo<'a; 'b>) {} | ^ expected one of `,` or `>` | help: use a comma to separate type parameters | LL | fn foo<'a, 'b>(_x: &mut Foo<'a, 'b>) {} | ~ error: aborting due to previous error