[boost] extra semicolons

From: Dave Steffen (dgsteffen_at_[hidden])
Date: 2005-07-18 13:37:15

Arkadiy Vertleyb writes:
 > Hi all,
 > 
 > Not having extra semicolons is one of the strongest arguments
 > against incuding a trailing semicolon into a statement-generating
 > macro.  Can anybody explain why having an extra semicolon is
 > considered a potential problem by some compilers?  Isn't null as
 > good as any other number?  Shouldn't an empty statement be
 > considered as good as any other statement?

 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. :-)

----------------------------------------------------------------------
Dave Steffen, Ph.D.       "There are two ways to write error-free
Software Engineer IV       programs; only the third one works."
Numerica Corporation            
ph [phone] x27     "Pie are not square. Pie are round. 
fax [phone]         Cornbread are square"
dgsteffen_at_[hidden]                    ... 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.