This header file is missing on most circa-2011 platforms.
@item
Clang 3.0's @code{<stdalign.h>} does not define @code{alignof}/@code{_Alignof}.
+@item
+The @code{alignof} and @code{_Alignof} macros return too large values for
+the types @code{double} and @code{long long} in GCC 4.7.0.
@end itemize
Portability problems not fixed by Gnulib:
Report Review Team assigned the internal review ID 2125432 (dated
2011-11-01) to this issue.
@item
-@code{<stdalign.h>} must be #included before @samp{_Alignas} and
-@samp{_Alignof} can be used.
+@code{<stdalign.h>} must be #included before @code{_Alignas} and
+@code{_Alignof} can be used.
@item
You cannot assume that @code{_Alignas} and @code{_Alignof} are reserved words;
they might be macros.