Problematic generation with multiple templates

[stuglaser]

I think I've found a case where autocxx mishandles multiple templates together (or it might be mishandling the default template):

class Thinger {
};

template <class T>
class RefPtr {
private:
    T* m_ptr;
};

class Container {
    void* data_;
};

class FakeAlloc {

};

template <typename T, typename A=FakeAlloc>
class Holder {
    A alloc;
};


typedef Holder<RefPtr<Thinger>> ThingerRefHolder;
class Problem {
public:
    ThingerRefHolder& getThingers();
};

This gives an error on build:

  cargo:warning=.../out/autocxx-build-dir/cxx/gen0.cxx: In function 'Holder_FakeAlloc_AutocxxConcrete* cxxbridge1$Problem$getThingers(Problem&)':
  cargo:warning=.../target/debug/build/repro-templvec-2d1a543db79e0eca/out/autocxx-build-dir/cxx/gen0.cxx:185:70: error: cannot convert 'ThingerRefHolder& (Problem::*)()' {aka 'Holder<RefPtr<Thinger> >& (Problem::*)()'} to 'Holder_FakeAlloc_AutocxxConcrete& (Problem::*)()' {aka 'Holder<FakeAlloc>& (Problem::*)()'} in initialization
  cargo:warning=  185 |   ::Holder_FakeAlloc_AutocxxConcrete &(::Problem::*getThingers$)() = &::Problem::getThingers;
  cargo:warning=      |                                                                      ^~~~~~~~~~~~~~~~~~~~~~~

I don't quite understand it, but I think the generation is skipping over the first template argument, and naming the type after only the second?

[adetaylor]

Thanks, please raise a PR with a test case.