ONIGENC_IS_CODE_UPPER  226 include/ruby/encoding.h #define rb_enc_isupper(c,enc) ONIGENC_IS_CODE_UPPER((enc),(c))
ONIGENC_IS_CODE_UPPER  424 regint.h          : (ONIGENC_IS_CODE_UPPER(enc,code) ? (code) - 'A' + 10 : (code) - 'a' + 10))