+/* Category: ctype builtins. */
+DEF_LIB_BUILTIN (BUILT_IN_ISALNUM, "isalnum", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISALPHA, "isalpha", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_EXT_LIB_BUILTIN (BUILT_IN_ISASCII, "isascii", BT_FN_INT_INT, ATTR_CONST_NOTHROW_LIST)
+DEF_C99_BUILTIN (BUILT_IN_ISBLANK, "isblank", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISCNTRL, "iscntrl", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISDIGIT, "isdigit", BT_FN_INT_INT, ATTR_CONST_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISGRAPH, "isgraph", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISLOWER, "islower", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISPRINT, "isprint", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISPUNCT, "ispunct", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISSPACE, "isspace", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISUPPER, "isupper", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_ISXDIGIT, "isxdigit", BT_FN_INT_INT, ATTR_CONST_NOTHROW_LIST)
+DEF_EXT_LIB_BUILTIN (BUILT_IN_TOASCII, "toascii", BT_FN_INT_INT, ATTR_CONST_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_TOLOWER, "tolower", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+DEF_LIB_BUILTIN (BUILT_IN_TOUPPER, "toupper", BT_FN_INT_INT, ATTR_PURE_NOTHROW_LIST)
+
+/* Category: wctype builtins. */
+DEF_C94_BUILTIN (BUILT_IN_ISWALNUM, "iswalnum", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWALPHA, "iswalpha", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C99_BUILTIN (BUILT_IN_ISWBLANK, "iswblank", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWCNTRL, "iswcntrl", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWDIGIT, "iswdigit", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWGRAPH, "iswgraph", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWLOWER, "iswlower", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWPRINT, "iswprint", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWPUNCT, "iswpunct", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWSPACE, "iswspace", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWUPPER, "iswupper", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_ISWXDIGIT, "iswxdigit", BT_FN_INT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_TOWLOWER, "towlower", BT_FN_WINT_WINT, ATTR_PURE_NOTHROW_LIST)
+DEF_C94_BUILTIN (BUILT_IN_TOWUPPER, "towupper", BT_FN_WINT_WINT, ATTR_PURE_NOTHROW_LIST)
+