- Didn't run at all (at least since v3.1) because of mismatch between
GlobalStorage constructor arguments and use; special-case None
in the C++ code to allocate a new GlobalStorage object.
In order to avoid deep copies, Qt containers over which we iterate must be const
The remaining unported cases require qAsConst (Qt 5.7) or std::as_const (C++17)
This allows us to make GlobalStorage a QObject, with disabled copy
constructor. And thanks to this change, GlobalStorage now emits
changed() every time an insert or remove is performed.
