error[E0106]: missing lifetime specifier --> $DIR/issue-19707.rs:13:28 | LL | type foo = fn(&u8, &u8) -> &u8; //~ ERROR missing lifetime specifier | ^ expected lifetime parameter | = help: this function's return type contains a borrowed value, but the signature does not say whether it is borrowed from argument 1 or argument 2 error[E0106]: missing lifetime specifier --> $DIR/issue-19707.rs:15:27 | LL | fn bar &u8>(f: &F) {} //~ ERROR missing lifetime specifier | ^ expected lifetime parameter | = help: this function's return type contains a borrowed value, but the signature does not say whether it is borrowed from argument 1 or argument 2 error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0106`.