Re: [boost] Macros at namespace scope: trailing semicolon?

From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2005-07-14 15:01:28

"David Abrahams" <dave_at_[hidden]> wrote

> I am defining a macro,
>
>   BOOST_PARAMETER_KEYWORD(tag_namespace, name)
>
> that declares a keyword for the Parameter library.  It has to be used
> at namespace scope.  I have the option to define it so that correct
> usage requires a trailing semicolon, or so that the trailing semicolon
> is forbidden.  Unfortunately I don't have the ability to make it
> optional.  Which should I choose?
>
> IMO there's no chance of confusing it with a function call, since a
> function call would be illegal in the context in which it's used, and
> people are naturally more likely to add a semicolon without thinking
> about it, and if I design the macro so that a semicolon is required it
> will interact more smoothly with editors and pretty-printers.  So I
> can't see any good reason not to require the semicolon.  Arguments?

One more option (probably an overkill):

#ifdef (BOOST_USE_TRAILING_SEMICOLON)
#    define BOOST_TRAILING_SEMICOLON ;
#else
#    define BOOST_TRAILING_SEMICOLON
#endif

Now end all your macro definitions with BOOST_TRAILING_SEMICOLON instead of
';', and the user can change the style with just one [un]define.

Regards,
Arkadiy