Re: [New module] Persistent Hash Array Mapped Tries (HAMTs)

[Paul Eggert]

On 10/10/20 8:04 AM, Marc Nieper-Wißkirchen wrote:
> #if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 201112L &&
> !defined (__STD_NO_ATOMICS__)
>
> I am asking because there may be non-C11 compilers that nevertheless
> understand _Atomic.

I suggest not worrying about this problem until we run into it. Quite possibly 
any actual problem will be something like "_Atomic can be used for most things, 
but not for feature X" in which case we'll likely want the more fine-grained 
check anyway. Until we discover actual problems we can get by with

   #if __STDC_VERSION__ < 201112 || defined __STD_NO_ATOMICS__

which is a cleaner way of writing the negative of the above test. These days 
there should be no reason to check whether __STDC_VERSION__ is defined, 
generally it's clearer to use "<" instead of ">=" so that textual order reflects 
numeric order, and the parens after "defined" are better omitted.