DBUS_ADAPTORS variable can't handle xml with multiple outputs

<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object Introspection 1.0//EN" "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
<node>
  <interface name="sample.client">
    <method name="dualOutputMethod">
      <arg type="b" direction="out"/>
      <arg type="i" direction="out"/>
    </method>
  </interface>
</node>

Here's a sample dbus xml with multiple output. This is handled just fine using DBUS_INTERFACES in the qt .pro file, but it isn't quite handled using DBUS_ADAPTORS (both undocumented...). I get output like this:

bool ClientAdaptor::dualOutputMethod(int &out1)
{
    // handle method call sample.client.dualOutputMethod
    //return static_cast<YourObjectType *>(parent())->dualOutputMethod(out1);
}

The solution I found online was to use the "-l" argument with qdbusxml2cpp, which would then mean I couldn't use DBUS_ADAPTORS anymore, and I'd have to implement some hack of using system calls in the header, or some other method of generating the cpp files. DBUS_ADAPTORS should be able to handle methods with multiple outputs, or someway to pass in the "-l" argument for that variable.

One other thing to note is that I originally had a custom abstract dbus adaptor which worked just fine with multiple outputs as a workaround to using this variable... In case more people stumble upon this issue and are looking for workarounds that work for them (http://doc.qt.io/qt-5/usingadaptors.html).