> At no point is there a need to edit a generated C++ file
Well then maybe your example should reflect that, where a change is made in the C++ file replacing 'Simple' with 'Time'
`src/main.cpp` is not a _generated_ C++ file.
It can be seen inside the template project here:
https://phabricator.kde.org/source/rust-qt-binding-generator...
At no point is there a need to edit a generated C++ file. Any other build tool with C++ support could be used instead of CMake. What it should do is call rust_qt_binding_generator when the binding description changes.
The table in this blog shows what files are generated: https://www.vandenoever.info/blog/2017/09/04/rust_qt_binding...