// error-pattern: requires `generator` lang_item | |
#![feature(no_core, lang_items, unboxed_closures)] | |
#![no_core] | |
#[lang = "sized"] pub trait Sized { } | |
#[lang = "fn_once"] | |
#[rustc_paren_sugar] | |
pub trait FnOnce<Args> { | |
type Output; | |
extern "rust-call" fn call_once(self, args: Args) -> Self::Output; | |
} | |
pub fn abc() -> impl FnOnce(f32) { | |
|_| {} | |
} | |
fn main() {} |