1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
#[lang = "sized"] pub trait Sized {} #[lang = "fn_once"] pub trait FnOnce<Args> { #[lang = "fn_once_output"] type Output; extern "rust-call" fn call_once(self, args: Args) -> Self::Output; } struct BinOpInvalid { lhs: i32, rhs: i32, f: impl FnOnce(i32) -> i32, // { dg-error ".impl Trait. not allowed outside of function and inherent method return types .E0562." } }