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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: Abstract Syntax Tree for C programs
Date: Tue, 04 Jun 2019 10:08:15 -0700
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Ben Bacarisse <ben.usenet@bsb.me.uk> writes:

> Bart <bc@freeuk.com> writes:
>
>> On 04/06/2019 07:56, Ike Naar wrote:
>>
>>> On 2019-06-03, Bart <bc@freeuk.com> wrote:
>>>
>>>> Using a void* to store a void(*)(void) is not a big deal, you
>>>> don't want -pedantic-errors to stop your build because of it.
>>>
>>> Using a function pointer (and not an object pointer) to store a
>>> function pointer isn't a big deal either.
>>
>> How would you create the following table:
>>
>>   void fn1(void){}
>>   void fn2(int a){}
>>   void fn3(int a,double b){}
>>   int fn4(void){return 0;}
>>   char* fn5(double a){return "";}
>>
>>   void* table[] = {fn1,fn2,fn3,fn4,fn5};
>>
>> Suggestions to use void(*)(void) for the table element aren't as
>> good.
>
> As good as what?
>
>> (Because you could actually write table[3]() without the compiler
>> picking that up.
>
> You simply can't do that in C.  If that is a deal-breaker, you
> need a different language.
>
> BTW, table[3]() would be a valid call, even in a version of C
> where every function pointer objects carried its own type around.

Do you mean to say it's okay to call fn4() through a void (*)(void)
function pointer, even though the return type of fn4() is int?  Or
was that just an oversight?  Or did I completely misunderstand you?