Re: in which we present an ugly hack to make sys/queue.h CIRCLEQ work

[Matthew Orgass <darkstar%city-net.com@localhost>]

2013-11-22 anthony.mallet%laas.fr@localhost wrote:
> On Thursday, at 23:56, Mouse wrote:
> | Yes, or at least wrong by that metric.  (The other 10% are things like
> | casting to char * and copying as a sequence of bytes, which I think is
> | exempted, though I don't recall details.
>
> Yes, (char *)ptr is an explicitly allowed exception.

  In gcq.h, I used (uint8_t *) instead of (char *) with offsetof and I see 
endian.h uses unit8_t to rearrange bytes.  It makes more sense that way 
IMO, but it sounds like it actually violates strict aliasing while using 
char wouldn't.  Does anyone with more in depth understanding know if this 
is this case?

-Matt

> C99:
> ``An object shall have its stored value accessed only by an lvalue expression
> that has one of the following types:
>
> - a type compatible with the effective type of the object,
> - a qualified version of a type compatible with the effective type of the 
> object,
> - a type that is the signed or unsigned type corresponding to the effective
>   type of the object,
> - a type that is the signed or unsigned type corresponding to a qualified
>   version of the effective type of the object,
> - an aggregate or union type that includes one of the aforementioned types
>   among its members (including, recursively, a member of a subaggregate or
>   contained union), or
> - a character type. ''