rust/src/test/ui/box/large-allocator-ice.rs

// build-pass
#![feature(allocator_api)]

use std::alloc::Allocator;

struct BigAllocator([usize; 2]);

unsafe impl Allocator for BigAllocator {
    fn allocate(
        &self,
        _: std::alloc::Layout,
    ) -> Result<std::ptr::NonNull<[u8]>, std::alloc::AllocError> {
        todo!()
    }
    unsafe fn deallocate(&self, _: std::ptr::NonNull<u8>, _: std::alloc::Layout) {
        todo!()
    }
}

fn main() {
    Box::new_in((), &std::alloc::Global);
    Box::new_in((), BigAllocator([0; 2]));
}