Arkadiy Vertleyb writes:
"Dave Steffen" <dgsteffen@numerica.us> wrote
Ths issue is IIRC and AFAIK macros that are used outside of any statement blocks, i.e. the thing David Abrahams suggested that spawned this whole thread. Something like a macro that declares or defines a function:
#define MAKEFOO inline void foo () { ... }
and then simply used as:
(... other inline functions, for example ...) MAKEFOO;
The point is that after macro expansion, that semicolon I put in after the macro invocation isn't valid, because I'm not allowed to have a null statement (or any other kind of statement) at this point in the file.
The presence or absence of that semicolon is what the fuss has been about. :-)
I tought it was about placing a trailing semicolon inside or outside a macro definition, something like:
#define MACRO struct x{}
versus
#define MACRO struct x{};
Ok, yes, that's another side of the issue. I should have been clearer. "The issue is" (take 2 :-) that there are some places where semicolons are required, and some where they are prohibited. Given the existence of macros, A) should macros intended for use in places where a trailing semicolon is mandated, include that semicolon in their definitions? B) should macros intended for use in place where trailing macros are prohibited, take steps to allow a trailing semicolon because some users of the macro would like to put one there?
My point is that it would be possible to have both possibilities if empty statements were allowd. The question was why are they not (by some compilers)?
... and what I attempted to say (and didn't very well) is that in places where null statements are allowed, yes, you're correct; the macro could include its own semicolon, and people who want add their own are allowed to.... ... with a few exceptions. As has been pointed out, if (something) MACRO_INVOCATION(); else ... is sensitive to how many semicolons end up at the end of the macro expansion. Whereas, in the case of function-defining macros and other odd things, you can't have a semicolon at all, because null statements aren't allowed there. The question of why anyone would add a semicolon after such a macro is sort of what the hubbub is about; some people like me think it looks natural, others like Paul think it's an abomination. :-) ---------------------------------------------------------------------- Dave Steffen, Ph.D. "There are two ways to write error-free Software Engineer IV programs; only the third one works." Numerica Corporation ph (970) 419-8343 x27 "Pie are not square. Pie are round. fax (970) 223-6797 Cornbread are square" dgsteffen@numerica.us ... anon (usenet) ___________________ Numerica Disclaimer: This message and any attachments are intended only for the individual or entity to which the message is addressed. It is proprietary and may contain privileged information. If you are neither the intended recipient nor the agent responsible for delivering the message to the intended recipient, you are hereby notified that any review, retransmission, dissemination, or taking of any action in reliance upon, the information in this communication is strictly prohibited, and may be unlawful. If you feel you have received this communication in error, please notify us immediately by returning this Email to the sender and deleting it from your computer.