SEGFAULT after generated proxy move about sdbus-cpp HOT 5 CLOSED

   UPower_proxy(sdbus::IProxy& proxy)
        : proxy_(&proxy)
    {
        proxy_->uponSignal("DeviceAdded").onInterface(INTERFACE_NAME).call([this](const sdbus::ObjectPath& device){
            this->onDeviceAdded(device);
         });
        proxy_->uponSignal("DeviceRemoved").onInterface(INTERFACE_NAME).call([this](const sdbus::ObjectPath& device){
            this->onDeviceRemoved(device);
         });
    }

for example if i generate this proxy based on Upower specification that gets notificed when a device is plugged in, the lambda in the constructor makes a copy of this, if i move this no longer works, kaput

my solution was to wrap my proxy in a unique_ptr, so i move the ptr, not the proxy itself.

from sdbus-cpp.

Thanks for reporting, yes, this is a bug. Generated adaptor and proxy classes cannot be moveable. Your solution with unique_ptr is the recommended solution in case move support is needed (e.g. when the proxy or adaptor instances are stored in a container).

from sdbus-cpp.

The fix will go into the soon-to-be-release v2.0.

from sdbus-cpp.

Thanks for the quick response @sangelovic,

It could still be possible to support moving by unregistering and re-registering, but not sure if that's worth the hassle

from sdbus-cpp.

@17steen Yes exactly, that would not be worth the hassle.

One problem could be that there is a thin time window where e.g. object's vtable is not registered. What if a D-Bus call comes just within that window? It would fail on nonexisting object, while that object is actually existing, just that it's being moved.
Or in case of a proxy, it would not listen to signals for that short time, but what if an (important) signal comes just in that window and it is not caught..?

This would thus be a fragile, error-prone solution opening up more problems than fixing.

from sdbus-cpp.