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From: kwh@bentley.UUCP
Newsgroups: net.lang.c
Subject: Re: Float Double Parameters
Message-ID: <676@bentley.UUCP>
Date: Fri, 28-Mar-86 15:17:23 EST
Article-I.D.: bentley.676
Posted: Fri Mar 28 15:17:23 1986
Date-Received: Tue, 1-Apr-86 07:11:40 EST
References: <2600042@ccvaxa>
Organization: AT&T Bell Laboratories, Liberty Corner
Lines: 26

In article <2600042@ccvaxa> ccvaxa!aglew writes:
>X3J11 says "arguments that have type float are promoted to double". Too bad.

I don't know anything about X3J11, but I thought ANSI C would allow the
declaration of arguments of extern functions, and would honor "float" if
so declared (but would continue to promote float to double for wild-card
arguments).

>Here is der Mouse's letter...
>>	foo(r) float r; { ... }

My own feeling is that it is WRONG to declare a float argument.  Since the
language automatically promotes (which I agree is poor design, though I
understand the reasons behind it), the variable "r" cannot possibly be a
float.  The compiler is being "nice" by letting you get away with it (it
"knows" that floats can't be passed by value, so it treats it as a double
declaration instead).  I think it should get a warning at least.

Similarly, I never declare a formal parameter as an array (e.g. char *argv[]).
It may very well be the name of an array that was passed by the caller, but
since it's automatically converted to a pointer, I prefer to declare the
formal as a pointer rather than letting the compiler translate the declaration
for me.  (Also, I could swear I once used a compiler that didn't treat arrays
and pointers identically as formal parameters.)

Karl W. Z. Heuer (ihnp4!bentley!kwh), The Walking Lint