Path: utzoo!attcan!uunet!husc6!bloom-beacon!oberon!sdcrdcf!hplabs!hpda!hpcupt1!hpcuhb!hpcllla!hpcllz2!walter
From: walter@hpcllz2.HP.COM (Walter Murray)
Newsgroups: comp.lang.c
Subject: Re: Casting function ptrs
Message-ID: <7330004@hpcllz2.HP.COM>
Date: 23 May 88 15:02:12 GMT
References: <281@marob.MASA.COM>
Organization: HP NSG/ISD Computer Language Lab
Lines: 31

chris@trantor.umd.edu (Chris Torek) writes:

>In article <7330003@hpcllz2.HP.COM> walter@hpcllz2.HP.COM (Walter Murray)
>writes:

>>... but I think the following has the virtue of being strictly
>>conforming per the dpANS. ...
>>
>>struct funcs {char *name; void (*func)();};
>>char *foo() {return "It worked!";};
>>struct funcs f = {"foo",(void(*)())foo};

>This is not strictly conforming, because the standard does not say
>whether objects of type `void (*)()' are in any way compatible with
>objects of type `char *(*)()'.  (It says very little about pointers
>to functions, no matter what the return type of the function....)
>
>Most likely, pointers to any function, no matter what the return
>type, will have the same format, but it would be nice to have some
>guarantees.

I was relying on the following statement from page 47 of the January
draft:  "A pointer to a function of one type may be converted to a
pointer to a function of another type and back again; the result
shall compare equal to the original pointer."

That sounds to me like a guarantee.  Did I read too much into it?

Walter Murray

All opinions expressed are my own.