https://github.com/therecipe/qt/blob/053d54a2eb0658bae6e3259...
All of the code is cgo wrappers around messes of c/c++
E.g. your project has `type Qt interface {`, and the plugin exports a global symbol that can be asserted to that interface to use the library.
[1]: https://golang.org/pkg/plugin/
https://github.com/therecipe/qt/blob/053d54a2eb0658bae6e3259...
All of the code is cgo wrappers around messes of c/c++