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From: hughes@ns.network.com (Jim Hughes x1676)
Newsgroups: comp.lang.c++
Subject: Re: default argument bug in 1.2!
Message-ID: <1505@ns.network.com>
Date: 24 Jul 89 14:22:12 GMT
References: <503@gill.UUCP> <6409@columbia.edu>
Sender: hughes@ns.network.com (Jim Hughes x1676)
Reply-To: hughes@ns.UUCP (Jim Hughes x1676)
Organization: Network Systems Corporation
Lines: 53

In article <6409@columbia.edu> kearns@read.UUCP (Steve Kearns) writes:
>
>Is there a workaround for the following bug?
>
>When I declare a member function to have a default constant argument,
>such as :
>
>class bar {
>		foo(int joe, int bill = -1);
>};
>
>
>Then the definition of foo usually contains a test like the following:
>
>   if (bill == -1) 
>		{ ...do this...}
>   else 
>        { ...do that...}
>
>The bug is that 1.2 seems to optimize out the if (bill == ..) test
>and include, in this case, only the first branch of the "if".  
>It seems to treat the "int bill = -1" declaration as if I was initializing
>a local variable.  
>
>Does anyone know any workarounds?
>-steve

I have compiled a test case, and found that this does not seem to be
an error as simple as you have stated.  The following complete program
works correctly and prints "bill != -1".

---------------------------
//test.c
#include <stdio.h>

class bar{
public:
  void foo(int joe, int bill= -1);
};

void bar.foo(int joe, int bill= -1) {
  if (bill == -1) printf("bill == -1\n");
  else printf("bill != -1\n");
}

main() {
  bar b;
  b.foo(23,24);
}
----------------------------

Jim
hughes@network.com