With a member function like this:

void foo(const QString& filename);

When changing it to:

void foo(const std::filesystem::path& filename);

and then clicking the light bulb that appears and selecting "Apply changes to definition", the function definition in the implementation cpp file gets converted to:

MyClass::foo(const std::filesystem::__cxx11::path& filename)

This only happens if `filename` is a reference type. If it's a value type, it works correctly (meaning you get `std::filesystem::path`, not `std::filesystem::__cxx11::path`.)