Add support for "direct" converters
diff --git a/include/pybind11/common.h b/include/pybind11/common.h
index 40cee87..be4633c 100644
--- a/include/pybind11/common.h
+++ b/include/pybind11/common.h
@@ -321,6 +321,7 @@
std::unordered_map<const void *, void*> registered_types_py; // PyTypeObject* -> type_info
std::unordered_multimap<const void *, void*> registered_instances; // void * -> PyObject*
std::unordered_set<std::pair<const PyObject *, const char *>, overload_hash> inactive_overload_cache;
+ std::unordered_map<std::type_index, std::vector<bool (*)(PyObject *, void *&)>> direct_conversions;
std::forward_list<void (*) (std::exception_ptr)> registered_exception_translators;
#if defined(WITH_THREAD)
decltype(PyThread_create_key()) tstate = 0; // Usually an int but a long on Cygwin64 with Python 3.x