In article <3ebcc5d1-a57d-a290-72d8-6efc73025...@gmx.com>,
Kamil Rytarowski <n...@gmx.com> wrote:
>-=-=-=-=-=-
>-=-=-=-=-=-
>
>On 11.08.2019 02:56, Valery Ushakov wrote:
>> Kamil Rytarowski <n...@gmx.com> wrote:
>>
>>> Cast of udata from void* to intptr_t shall be done with
>>> reinterpret_cast<> otherwise a C++ compiler errors.
>>>
>>> Defining __REINTERPRET_CAST [1] and using it, did not work as a compiler
>>> protested for NULL argument "warning: passing NULL to non-pointer argument".
>>>
>>> Using double cast __REINTERPRET_CAST(intptr_t, __CAST(void *, (udata)))
>>> pacified the warning/error about passing NULL in C++, but it created the
>>> problem of calling EV_SET using the native argument type intptr_t.
>>
>> You are reporting quite an abstract summary that is not so easy to
>> follow for someone who hasn't done all the same experiments that you
>> already have done.
>
>
>$ cat /tmp/test.cpp
>
>
>#include <sys/types.h>
>#include <sys/event.h>
>
>int
>main(int argc, char **argv)
>{
> struct kevent kv;
>
> EV_SET(&kv, 0, 0, 0, 0, 0, 0);
> EV_SET(&kv, 0, 0, 0, 0, 0, NULL);
> EV_SET(&kv, 0, 0, 0, 0, 0, nullptr);
> EV_SET(&kv, 0, 0, 0, 0, 0, 0L);
> EV_SET(&kv, 0, 0, 0, 0, 0, 0LL);
> EV_SET(&kv, 0, 0, 0, 0, 0, 0U);
> EV_SET(&kv, 0, 0, 0, 0, 0, 0UL);
> EV_SET(&kv, 0, 0, 0, 0, 0, 0ULL);
> EV_SET(&kv, 0, 0, 0, 0, 0, (intptr_t)0);
> EV_SET(&kv, 0, 0, 0, 0, 0, (uintptr_t)0);
>
>
> return 0;
>}
How about:
EV_SET(&kv, 0, 0, 0, 0, 0, 'a');
EV_SET(&kv, 0, 0, 0, 0, 0, 0.0);
and all the other integral types not mentiones above?
So if we are going to go gung ho C++, why not do it as a template?
You could also possibly use std::is_integral (or the c++17 std::is_integral_v)
etc., and perhaps get rid of the diagnostic suppression :-)
christos
