This is an example of AOSP Native Service and binder. There are two APIs defined in Native Service. The return value of one is a class. Parcelable is used for this.

PackageInfo.aidl

parcelable PackageInfo cpp_header "include/PackageInfo.h";

PackageInfo.h

class PackageInfo: public android::Parcelable

The other also uses callback.

IBinderCommCallback.aidl

interface IBinderCommCallback {
    void onChangeEvent(int event);
}

IBinderCommService.aidl

void registerCallback(IBinderCommCallback callback);

BinderCommService.h

class BinderCommService : public com::cb::BnBinderCommService,...
{
...
virtual android::binder::Status registerCallback(const android::sp<::com::cb::IBinderCommCallback>& callback) override;
}

There is also a client application for Android.