X-Git-Url: https://git.ralfj.de/web.git/blobdiff_plain/cd545f1d8766d3326725bca9e3cc898eeac387fd..3e85bae4c4ab1210c762179470cdce11d5baa118:/personal/_posts/2019-07-14-uninit.md?ds=sidebyside diff --git a/personal/_posts/2019-07-14-uninit.md b/personal/_posts/2019-07-14-uninit.md index 0b16076..b25a052 100644 --- a/personal/_posts/2019-07-14-uninit.md +++ b/personal/_posts/2019-07-14-uninit.md @@ -54,7 +54,7 @@ However, if you [run the example](https://play.rust-lang.org/?version=stable&mod ## What *is* uninitialized memory? How is this possible? -The answer is that, in the "abstract machine" that is used to specify the behavior of our program, every byte in memory cannot just have a value in `0..256` (this is Rust/Ruby syntax for a left-inclusive right-exclusive range), it can also be "uninitialized". +The answer is that, in the "abstract machine" that is used to specify the behavior of our program, every byte in memory cannot just have a value in `0..256` (this is Rust syntax for a left-inclusive right-exclusive range), it can also be "uninitialized". Memory *remembers* if you initialized it. The `x` that is passed to `always_return_true` is *not* the 8-bit representation of some number, it is an uninitialized byte. Performing operations such as comparison on uninitialized bytes is [undefined behavior]({% post_url 2017-07-14-undefined-behavior %}).