[barskern]

Isn't the following statement always true, as casting using `as` will silently ~~overflow~~ truncate the `u32` if `usize` is 64-bits?

    assert!((samples as u32) <= u32::MAX);

EDIT: I know it's a contrived example, but I was just curious if my understanding is correct. I also found this page in the nomicon about casting: https://doc.rust-lang.org/nomicon/casts.html

EDIT2: As I thought casting a `usize` which is 64-bits to a `u32` causes it to be truncated and hence the assertion is always true. Further by using a number that's bigger than a `u32`, this example contains undefined behavior. This is due to the use of `slice::from_raw_parts` where `self.samples` is left as a `usize` and hence takes a much bigger slice than what was allocated (the leftover of the truncate operation). I made a small playground which demonstrates the segfault. https://play.rust-lang.org/?version=stable&mode=debug&editio.... The assertion should rather be:

    assert!(samples <= u32::MAX as usize);

Don't get me wrong, I think the blogpost is a great explanatory article about memory ordering and the example is rather contrived. I just wanted to reassure myself that my understanding was correct and further perhaps help someone not seeing this issue (as this is a very easy trap to fall into).

[redbluemonkey]

You are correct. Thanks for the pickup. Fixed the post and repo.

[estebank]

To be honest, this check deserves to be in clippy.