incorrect result on some platforms:
AIX 5.2, OSF/1 5.1, Solaris 11 2011-11, mingw, MSVC 9.
@item
+printf of @samp{long double} numbers outside the IEEE 754 range produces
+no meaningful results on some platforms:
+glibc and others, on x86, x86_64, IA-64 CPUs.
+@item
This function does not support the @samp{a} and @samp{A} directives on some
platforms:
glibc-2.3.6, MacOS X 10.5, NetBSD 5.0, OpenBSD 4.0, AIX 5.2, HP-UX 11,