Re: [PATCH 2/2] system_data_types.7: void *: Add info about pointer artihmetic

[Alejandro Colomar]

Hi Michael,

The 2/2 is a typo.  This is a standalone patch.

Cheers,

Alex

On 2020-10-02 11:44, Alejandro Colomar wrote:
> Reported-by: Paul Eggert <eggert@xxxxxxxxxxx>
> Reported-by: David Laight <David.Laight@xxxxxxxxxx>
> Signed-off-by: Alejandro Colomar <colomar.6.4.3@xxxxxxxxx>
> ---
>
> Paul and David,
> Thanks for your input!
>
> Alex
>
>
>   man7/system_data_types.7 | 11 +++++++++++
>   1 file changed, 11 insertions(+)
>
> diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
> index 6451782db..bc7d5a8a0 100644
> --- a/man7/system_data_types.7
> +++ b/man7/system_data_types.7
> @@ -1918,6 +1918,17 @@ A value of this type can't be dereferenced,
>   as it would give a value of type
>   .I void
>   which is not possible.
> +Likewise, pointer arithmetic is not possible with this type.
> +However, in GNU C, poitner arithmetic is allowed
> +as an extension to the standard;
> +this is done by treating the size of a
> +.I void
> +or of a function as 1.
> +A consequence of this is that
> +.I sizeof
> +is also allowed on
> +.I void
> +and on function types, and returns 1.
>   .PP
>   The conversion specifier for
>   .I void *