The way to guarantee the the safety of alignment issues

[shinmao]

grcov/src/reader.rs

Lines 169 to 177 in 322fc39

	($ty: ty, $buf: expr) => {{
	let size = std::mem::size_of::<$ty>();
	let start = $buf.pos;
	$buf.pos += size;
	if $buf.pos <= $buf.buffer.len() {
	let val: $ty = unsafe {
	// data are aligned so it's safe to do that
	#[allow(clippy::transmute_ptr_to_ptr)]
	*std::mem::transmute::<*const u8, *const $ty>($buf.buffer[start..].as_ptr())

Hi, I am interested in the way you guarantee the safety of alignment issues. Take read_u32 for example, we are worried that the data is aligned to 1 byte rather than 4 bytes here. Do you use the offset starting from 4 bytes with buffer[start..] to solve the issue?

In other words, if we use transmute($buf.buffer.as_ptr()), then it is still dangerous?