#![allow(unused_variables)] #![feature(allocator_api)] fn main() { fn _inner() -> core::result::Result<(), impl core::fmt::Debug> { use std::alloc::System; let zero = Box::::try_new_zeroed_in(System)?; let zero = unsafe { zero.assume_init() }; assert_eq!(* zero, 0); Ok::<(), std::alloc::AllocError>(()) } _inner().unwrap() }