From 6dea65fe64d4e11f78be6fc025bfb86b4a7eab2f Mon Sep 17 00:00:00 2001
From: "Ralf W. Grosse-Kunstleve" <rwgk@google.com>
Date: Tue, 12 Jan 2021 13:45:48 -0800
Subject: [PATCH] static cast handle for rtrn_cref works by simply dropping in
 code from type_caster_base (marked with comments). rtrn_mref and rtrn_mptr
 work via const_cast (to add const).

---
 tests/test_classh_wip.cpp | 18 ++++++++++++------
 tests/test_classh_wip.py  |  6 +++---
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/tests/test_classh_wip.cpp b/tests/test_classh_wip.cpp
index 58d991bd8..d974452da 100644
--- a/tests/test_classh_wip.cpp
+++ b/tests/test_classh_wip.cpp
@@ -78,12 +78,18 @@ struct type_caster<mpty> : smart_holder_type_caster_load<mpty> {
         return str("cast_rref").release();
     }
 
-    static handle cast(mpty const & /*src*/, return_value_policy /*policy*/, handle /*parent*/) {
-        return str("cast_cref").release();
+    static handle cast(mpty const &src, return_value_policy policy, handle parent) {
+        // type_caster_base BEGIN
+        // clang-format off
+        if (policy == return_value_policy::automatic || policy == return_value_policy::automatic_reference)
+            policy = return_value_policy::copy;
+        return cast(&src, policy, parent);
+        // clang-format on
+        // type_caster_base END
     }
 
-    static handle cast(mpty & /*src*/, return_value_policy /*policy*/, handle /*parent*/) {
-        return str("cast_mref").release();
+    static handle cast(mpty &src, return_value_policy policy, handle parent) {
+        return cast(const_cast<mpty const &>(src), policy, parent); // Mtbl2Const
     }
 
     static handle cast(mpty const *src, return_value_policy policy, handle parent) {
@@ -97,8 +103,8 @@ struct type_caster<mpty> : smart_holder_type_caster_load<mpty> {
         // type_caster_base END
     }
 
-    static handle cast(mpty * /*src*/, return_value_policy /*policy*/, handle /*parent*/) {
-        return str("cast_mptr").release();
+    static handle cast(mpty *src, return_value_policy policy, handle parent) {
+        return cast(const_cast<mpty const *>(src), policy, parent); // Mtbl2Const
     }
 
     template <typename T_>
diff --git a/tests/test_classh_wip.py b/tests/test_classh_wip.py
index 719b303a8..10a42ae9d 100644
--- a/tests/test_classh_wip.py
+++ b/tests/test_classh_wip.py
@@ -16,10 +16,10 @@ def test_mpty_constructors():
 def test_cast():
     assert m.rtrn_mpty_valu() == "cast_rref"
     assert m.rtrn_mpty_rref() == "cast_rref"
-    assert m.rtrn_mpty_cref() == "cast_cref"
-    assert m.rtrn_mpty_mref() == "cast_mref"
+    assert m.get_mtxt(m.rtrn_mpty_cref()) == "rtrn_cref"
+    assert m.get_mtxt(m.rtrn_mpty_mref()) == "rtrn_mref"
     assert m.get_mtxt(m.rtrn_mpty_cptr()) == "rtrn_cptr"
-    assert m.rtrn_mpty_mptr() == "cast_mptr"
+    assert m.get_mtxt(m.rtrn_mpty_mptr()) == "rtrn_mptr"
 
 
 def test_load():