Re: Lisp object that refers to a C struct

[Eli Zaretskii]

> Date: Thu, 18 Oct 2012 09:42:14 -0700
> From: Paul Eggert <address@hidden>
> CC: address@hidden
> 
> On 10/18/2012 04:09 AM, Eli Zaretskii wrote:
> >> but in general it's not safe to convert a pointer to
> >> > an Emacs fixnum, as this can lose information: the payload
> >> > of an Emacs fixnum is typically narrower than a pointer.
> > A pointer that is properly aligned has no problem with this.
> 
> It can have problems on hosts where USE_LSB_TAG is 0,
> because the conversion to Emacs fixnum can lose high-order
> bits in the pointer.

We are talking about Windows-specific code, so I don't think this
danger is real.