from ctype.h. Initially, the approach was to produce an error when
detecting that ctype.h has been included. But this was causing
trouble as ctype.h might get indirectly included as a result of
- including another system header (for instance gnulib's stdint.h). */
+ including another system header (for instance gnulib's stdint.h).
+ So we include ctype.h here and then immediately redefine its macros. */
+
+#include <ctype.h>
#undef isalpha
#define isalpha(c) do_not_use_isalpha_with_safe_ctype
#undef isalnum