We notice that the following code is accepted by Borland's C++ compilers:

class C { public: ~C() {} };
void foo {
  const C *p = new C;
  delete p;
}

Is this a reflection of (or anticipation of) a proposed change to the
rule that a pointer to constant cannot be deleted (ARM 5.3.4)?  If so,
could we get a summary of the reasoning behind the change?

/*----------------------------------------------------------------------*/
/* Bob Kline                                           CSI Technologies */
/* bkline@smtp.csof.com                        Corporate Software, Inc. */
/* voice: (703) 522-0820                            fax: (703) 522-5407 */
/*----------------------------------------------------------------------*/

In article <1994Jun8.154954.9386@nlm.nih.gov>,
Bob Kline <bkline%occs.nlm.nih.gov> wrote:
>
>We notice that the following code is accepted by Borland's C++ compilers:
>
>class C { public: ~C() {} };
>void foo {
>  const C *p = new C;
>  delete p;
>}
>

 If you compile with -A (strict ANSI/ISO compliance) this code is not
accepted.
 -- Pete

Pete Becker (pete@genghis.interbase.borland.com) wrote:
: In article <1994Jun8.154954.9386@nlm.nih.gov>,
: Bob Kline <bkline%occs.nlm.nih.gov> wrote:
: >
: >We notice that the following code is accepted by Borland's C++ compilers:
: >
: >class C { public: ~C() {} };
: >void foo {
: >  const C *p = new C;
: >  delete p;
: >}
: >

:  If you compile with -A (strict ANSI/ISO compliance) this code is not
: accepted.

Thanks.  Can you shed any light on why the compiler needs the flag
to recognize the illegal code in this case but does not need the flag
if the destructor is omitted?  What's the rationale behind the
different behavior?

/*----------------------------------------------------------------------*/
/* Bob Kline                                           CSI Technologies */
/* bkline@smtp.csof.com                        Corporate Software, Inc. */
/* voice: (703) 522-0820                            fax: (703) 522-5407 */
/*----------------------------------------------------------------------*/

In article <1994Jun9.114835.9201@nlm.nih.gov>,
Bob Kline <bkline%occs.nlm.nih.gov> wrote:
>Pete Becker (pete@genghis.interbase.borland.com) wrote:
>: In article <1994Jun8.154954.9386@nlm.nih.gov>,
>: Bob Kline <bkline%occs.nlm.nih.gov> wrote:
>: >
>: >We notice that the following code is accepted by Borland's C++ compilers:
>: >
>: >class C { public: ~C() {} };
>: >void foo {
>: >  const C *p = new C;
>: >  delete p;
>: >}
>: >
>
>:  If you compile with -A (strict ANSI/ISO compliance) this code is not
>: accepted.
>
>Thanks.  Can you shed any light on why the compiler needs the flag
>to recognize the illegal code in this case but does not need the flag
>if the destructor is omitted?  What's the rationale behind the
>different behavior?

 The compiler doesn't "need" the flag to recognize illegal code. This
is a compatibility switch to avoid breaking existing code.
 -- Pete

Pete Becker (pete@genghis.interbase.borland.com) wrote:
: In article <1994Jun9.114835.9201@nlm.nih.gov>,
: Bob Kline <bkline%occs.nlm.nih.gov> wrote:
:
: >Thanks.  Can you shed any light on why the compiler needs the flag
: >to recognize the illegal code in this case but does not need the flag
: >if the destructor is omitted?  What's the rationale behind the
: >different behavior?

:  The compiler doesn't "need" the flag to recognize illegal code. This
: is a compatibility switch to avoid breaking existing code.
:  -- Pete

Does this mean that it used to be legal to delete a const object if
the object had a destructor, but illegal if it didn't have one?

Also, wouldn't it be appropriate to at least issue a warning
(particularly when the flag for the maximum warning level has been
used) when the compiler encounters illegal code?


/*----------------------------------------------------------------------*/
/* Bob Kline                                           CSI Technologies */
/* bkline@smtp.csof.com                        Corporate Software, Inc. */
/* voice: (703) 522-0820                            fax: (703) 522-5407 */
/*----------------------------------------------------------------------*/