-AC_MSG_CHECKING([for size of bool])
-AC_CACHE_VAL(cf_cv_type_of_bool,[
+AC_CHECK_SIZEOF(bool,,[
+#include <stdlib.h>
+#include <stdio.h>
+
+#if defined(__cplusplus)
+
+#ifdef HAVE_GXX_BUILTIN_H
+#include <g++/builtin.h>
+#elif HAVE_GPP_BUILTIN_H
+#include <gpp/builtin.h>
+#elif HAVE_BUILTIN_H
+#include <builtin.h>
+#endif
+
+#else
+
+#if $cf_cv_header_stdbool_h
+#include <stdbool.h>
+#endif
+
+#endif
+])
+
+AC_CACHE_CHECK(for type of bool, cf_cv_type_of_bool,[