[rust-dev] read_byte and sentinel values

Corey Richardson corey at octayn.net
Wed Jul 24 09:46:20 PDT 2013


On Wed, Jul 24, 2013 at 12:42 PM, Matthieu Monrocq
<matthieu.monrocq at gmail.com> wrote:
> Given that all values of u8 are meanginful, there is no space for an extra
> bit, so it is no surprise that it cannot be packed.
>
> For pointers, for example, it is typical to exploit the fact that the null
> pointer is a meaningless value and thus rely on this sentinel value to
> encode the absence of value, but in general this is only possible if such a
> sentinel value is possible to begin with.
>

I would expect it to be backed into a u16.


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