<?xml version="1.0"?>
<!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="some.interface.Foo">
    <method name="GetValues">
    <arg name="values" type="a(oa{sv})" direction="out"/>
        <annotation name="org.qtproject.QtDBus.QtTypeName.Out0" value="QList<SomeStruct>" />
    </method>
</interface>
</node>

qdbusxml2cpp-qt5 -c InterfaceFoo -p interface_foo  foo.xml

class InterfaceFoo: public QDBusAbstractInterface
{
    Q_OBJECT
public:
    static inline const char *staticInterfaceName()
    { return "some.interface.Foo"; }

public:
    InterfaceFoo(const QString &service, const QString &path, const QDBusConnection &connection, QObject *parent = 0);

    ~InterfaceFoo();

public Q_SLOTS: // METHODS
    inline QDBusPendingReply<QList<SomeStruct> > GetValues()
    {
        QList<QVariant> argumentList;
        // NOTICE THIS LINE.
        return asyncCallWithArgumentList(QStringLiteral("GetValues"), argumentList);
    }

Q_SIGNALS: // SIGNALS
};

namespace some {
namespace interface {
    typedef ::InterfaceFoo Foo;
}
}
#endif

some::interface::Foo *interface =  new some::interface::Foo("some::interface", "/Foo", QDBusConnection::systemBus(), this);
 // THIS SHOULD block until a reply is received or it times out.
 QList<SomeStruct> data = interface->GetValues();