restrict vs. __restrict__ (gcc 4.8)

[Jonathan Wakely]

On 17 July 2017 at 15:13, Ian Pilcher wrote:
> I just discovered that gcc 4.8 (on CentOS 7) does not support the C99
> restrict keyword, at least not without -std=c99.

Because you're not compiling C99 otherwise.

> __restrict__ seems to work (in the sense that it compiles without
> errors), but I haven't been able to find anything that describes exactly
> what the difference between __restrict__ and restrict is (if any).

The latter is only available from C99, I'm pretty sure that's all.

> Am I safe simply replacing restrict with __restrict__?  (I can't easily
> use -sdt=c99, because it seems to disable the typeof operator.)

Can't you use -std=gnu99 then?