Path: utzoo!utgpu!watserv1!watmath!att!att!linac!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!ncar!groucho!steve
From: steve@groucho.ucar.edu (Steve Emmerson)
Newsgroups: comp.lang.c
Subject: Re: is (int (*)())NULL legal when NULL is (void *)0?
Message-ID: <9208@ncar.ucar.edu>
Date: 18 Nov 90 02:51:49 GMT
References: <14484@smoke.brl.mil> <14498@smoke.brl.mil> <27780@mimsy.umd.edu> <14517@smoke.brl.mil>
Sender: news@ncar.ucar.edu
Organization: University Corporation for Atmospheric Research (UCAR)
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In <14517@smoke.brl.mil> gwyn@smoke.brl.mil (Doug Gwyn) writes:

>In article <27780@mimsy.umd.edu> chris@mimsy.umd.edu (Chris Torek) writes:
>>This would make it difficult to pass a `nil pointer to function of no
>>arguments returning int' to a function for which no prototype can be
>>provided.

>But not impossible, as a suitable pointer variable initialized to a null
>pointer (trivially accomplished) could be used.  You could even define
>it to be const-qualified and hope the compiler is good at optimizations.

Whoa!  So the following is non-conforming:

    foo((int((*)(void)))NULL)

where the prototype for foo() isn't in scope and it takes the indicated
argument type.

This has implications for those of us who, at least, *try* to write 
portable code (though, as Doug indicated, the problem is avoidable).

Are you sure of this, Doug?  Or do we need an Official Ruling?  

I know.  When in doubt, request a ruling ;-).

Steve Emmerson        steve@unidata.ucar.edu        ...!ncar!unidata!steve