inspect

static VALUE
enc_inspect(VALUE self)
{
    VALUE str = rb_sprintf("#<%s:%s%s>", rb_obj_classname(self),
                      rb_enc_name((rb_encoding*)DATA_PTR(self)),
                      (enc_dummy_p(self) ? " (dummy)" : ""));
    ENCODING_CODERANGE_SET(str, rb_usascii_encindex(), ENC_CODERANGE_7BIT);
    return str;
}