Gets back user data pointers stored via ParamSpec.setQdata
and removes the data from pspec without invoking its destroy()
function (if any was set). Usually, calling this function is only
required to update user data pointers with a destroy notifier.
Gets back user data pointers stored via ParamSpec.setQdata and removes the data from pspec without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier.