bpo-36097: Use only public C-API in the_xxsubinterpreters module (adding as necessary). (gh-12359)
diff --git a/Include/cpython/interpreteridobject.h b/Include/cpython/interpreteridobject.h
new file mode 100644
index 0000000..cb72c2b
--- /dev/null
+++ b/Include/cpython/interpreteridobject.h
@@ -0,0 +1,21 @@
+#ifndef Py_CPYTHON_INTERPRETERIDOBJECT_H
+# error "this header file must not be included directly"
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Interpreter ID Object */
+
+PyAPI_DATA(PyTypeObject) _PyInterpreterID_Type;
+
+PyAPI_FUNC(PyObject *) _PyInterpreterID_New(int64_t);
+PyAPI_FUNC(PyObject *) _PyInterpreterState_GetIDObject(PyInterpreterState *);
+PyAPI_FUNC(PyInterpreterState *) _PyInterpreterID_LookUp(PyObject *);
+
+PyAPI_FUNC(int64_t) _Py_CoerceID(PyObject *);
+
+#ifdef __cplusplus
+}
+#endif