struct Wrapper<'rom>(&'rom ()); trait Foo { fn bar() -> Wrapper; //~^ ERROR missing lifetime specifier //~| ERROR struct takes 0 generic arguments but 1 generic argument was supplied } impl Foo for () { fn bar() -> i32 { 0 } } trait Bar { fn foo() -> Wrapper; //~^ ERROR missing lifetime specifier //~| ERROR struct takes 0 generic arguments but 1 generic argument was supplied } impl Bar for () { fn foo() -> Wrapper { //~^ ERROR missing lifetime specifier //~| ERROR struct takes 0 generic arguments but 1 generic argument was supplied Wrapper(&()) } } fn main() {}