http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59357
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
It is documented in the next page:
http://gcc.gnu.org/onlinedocs/cpp/Alternatives-to-Wrapper-_0023ifndef.html#Alternatives-to-Wrapper-_0023ifndef
Another way to prevent a header file from being included more than once is with
the ‘#pragma once’ directive. If ‘#pragma once’ is seen when scanning a header
file, that file will never be read again, no matter what.
‘#pragma once’ does not have the problems that ‘#import’ does, but it is not
recognized by all preprocessors, so you cannot rely on it in a portable
program.
