rust/tests/pass/align.rs
2022-06-01 10:53:38 -04:00

26 lines
737 B
Rust

/// This manually makes sure that we have a pointer with the proper alignment.
fn manual_alignment() {
let x = &mut [0u8; 3];
let base_addr = x as *mut _ as usize;
let base_addr_aligned = if base_addr % 2 == 0 { base_addr } else { base_addr+1 };
let u16_ptr = base_addr_aligned as *mut u16;
unsafe { *u16_ptr = 2; }
}
/// Test standard library `align_to`.
fn align_to() {
const LEN: usize = 128;
let buf = &[0u8; LEN];
let (l, m, r) = unsafe { buf.align_to::<i32>() };
assert!(m.len()*4 >= LEN-4);
assert!(l.len() + r.len() <= 4);
}
fn main() {
// Do this a couple times in a loop because it may work "by chance".
for _ in 0..10 {
manual_alignment();
align_to();
}
}