Conversion function redefinition error when handling C++ types

[KmolYuan]

I have a extension class which including C++ member (std::vector<my_struct>, and my_struct has some std::pair<int, int> members).
And there also has a std::pair<int, int> type definition in the same source.

I'm found that the conversion function (std::pair<int, int> to tuple[int, int]) is defined twice unless added @cython.auto_pickle(False) on my extension class.

11510:18: error: redefinition of 'PyObject* __pyx_convert_pair_to_py_int____int(const std::pair<int, int>&)'
 static PyObject *__pyx_convert_pair_to_py_int____int(std::pair<int,int>  const &__pyx_v_p) {
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10055:18: note: 'PyObject* __pyx_convert_pair_to_py_int____int(const std::pair<int, int>&)' previously defined here
 static PyObject *__pyx_convert_pair_to_py_int____int(std::pair<int,int>  const &__pyx_v_p) {
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I'm not clearly know how Cython checks the tool functions of ctypedef.
In another case My extension members are sharing a same ctypedef with local variables, but this error is not occurred.

[KmolYuan]

When I'm using vector[pair[int, int]] and map[int, bint] in the same file, the error comes again.
Regardless creating type alias or using original form can't solve the problem.

Maybe somewhere Cython treats bint as a different type when generating conversion functions.

[da-woods]

This looks like substantially the same issue as #3716 and #3734. The problem is where Cython utility code is itself generating utility code. Each lot of 2nd-level generated utility code is generated without access to the full module scope so can end up sharing names.

I'll try to have a look at it in the near future. Although it looked trick to solve last time I looked

[KmolYuan]

My case is little complex, which mixed a lot of functions and cannot extracted to a small one.
I'm not actually know what cause the duplicated code in my module.

The repo is here, change this line from Status & to object can reproduce the error: (build by setup.py)
https://github.com/KmolYuan/pyslvs/blob/master/pyslvs/topo_config.pyx#L187

But this error does not bother me at the moment.