struct Foo<'a>(&'a u8); struct Baz<'a>(&'_ &'a u8); //~ ERROR missing lifetime specifier fn foo<'_> //~ ERROR cannot be used here (_: Foo<'_>) {} trait Meh<'a> {} impl<'a> Meh<'a> for u8 {} fn meh() -> Box Meh<'_>> //~ ERROR cannot be used here //~^ ERROR missing lifetime specifier { Box::new(5u8) } fn foo2(_: &'_ u8, y: &'_ u8) -> &'_ u8 { y } //~ ERROR missing lifetime specifier fn main() { let x = 5; foo(Foo(&x)); let _ = meh(); }