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use core::alloc::Layout;
use core::ptr::{self, NonNull};
#[test]
fn const_unchecked_layout() {
const SIZE: usize = 0x2000;
const ALIGN: usize = 0x1000;
const LAYOUT: Layout = unsafe { Layout::from_size_align_unchecked(SIZE, ALIGN) };
const DANGLING: NonNull<u8> = LAYOUT.dangling();
assert_eq!(LAYOUT.size(), SIZE);
assert_eq!(LAYOUT.align(), ALIGN);
assert_eq!(Some(DANGLING), NonNull::new(ptr::invalid_mut(ALIGN)));
}
#[test]
fn layout_debug_shows_log2_of_alignment() {
// `Debug` is not stable, but here's what it does right now
let layout = Layout::from_size_align(24576, 8192).unwrap();
let s = format!("{:?}", layout);
assert_eq!(s, "Layout { size: 24576, align: 8192 (1 << 13) }");
}
// Running this normally doesn't do much, but it's also run in Miri, which
// will double-check that these are allowed by the validity invariants.
#[test]
fn layout_accepts_all_valid_alignments() {
for align in 0..usize::BITS {
let layout = Layout::from_size_align(0, 1_usize << align).unwrap();
assert_eq!(layout.align(), 1_usize << align);
}
}
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