From eb15f1a384a89bd2f9c20e4ba958233ae6d3247a Mon Sep 17 00:00:00 2001
From: "Ralf W. Grosse-Kunstleve" <rwgk@google.com>
Date: Sat, 6 Jul 2024 14:29:22 -0700
Subject: [PATCH] WIP: remove convert_type() call from loaded_as_shared_ptr()

---
 include/pybind11/cast.h                    | 32 +++++++++++-----------
 include/pybind11/detail/type_caster_base.h |  6 ++--
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/include/pybind11/cast.h b/include/pybind11/cast.h
index 1bdd9a483..18c96d293 100644
--- a/include/pybind11/cast.h
+++ b/include/pybind11/cast.h
@@ -794,11 +794,11 @@ protected:
         }
     }
 
-    bool load_value(value_and_holder &&v_h) {
+    void load_value(value_and_holder &&v_h) {
         if (v_h.holder_constructed()) {
             value = v_h.value_ptr();
             holder = v_h.template holder<holder_type>();
-            return true;
+            return;
         }
         throw cast_error("Unable to cast from non-held to held instance (T& to Holder<T>) "
 #if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
@@ -848,6 +848,9 @@ public:
     using base::value;
 
     bool load(handle src, bool convert) {
+        if (typeinfo->default_holder) {
+            return type_caster_generic::load(src, convert);
+        }
         return base::template load_impl<copyable_holder_caster<type, std::shared_ptr<type>>>(
             src, convert);
     }
@@ -877,7 +880,7 @@ public:
 
     explicit operator std::shared_ptr<type> &() {
         if (typeinfo->default_holder) {
-            shared_ptr_holder = sh_load_helper.loaded_as_shared_ptr();
+            shared_ptr_holder = sh_load_helper.loaded_as_shared_ptr(value);
         }
         return shared_ptr_holder;
     }
@@ -900,11 +903,11 @@ protected:
     friend class type_caster_generic;
     void check_holder_compat() {}
 
-    bool load_value_shared_ptr(const value_and_holder &v_h) {
+    void load_value_shared_ptr(const value_and_holder &v_h) {
         if (v_h.holder_constructed()) {
             value = v_h.value_ptr();
             shared_ptr_holder = v_h.template holder<std::shared_ptr<type>>();
-            return true;
+            return;
         }
         throw cast_error("Unable to cast from non-held to held instance (T& to Holder<T>) "
 #if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
@@ -916,16 +919,13 @@ protected:
 #endif
     }
 
-    bool load_value_smart_holder(const value_and_holder &v_h) {
-        sh_load_helper.loaded_v_h = v_h;
-        return true;
-    }
-
-    bool load_value(value_and_holder &&v_h) {
+    void load_value(value_and_holder &&v_h) {
         if (typeinfo->default_holder) {
-            return load_value_smart_holder(v_h);
+            sh_load_helper.loaded_v_h = v_h;
+            type_caster_generic::load_value(std::move(v_h));
+            return;
         }
-        return load_value_shared_ptr(v_h);
+        load_value_shared_ptr(v_h);
     }
 
     template <typename T = std::shared_ptr<type>,
@@ -938,7 +938,7 @@ protected:
               detail::enable_if_t<std::is_constructible<T, const T &, type *>::value, int> = 0>
     bool try_implicit_casts(handle src, bool convert) {
         if (typeinfo->default_holder) {
-            throw std::runtime_error("BAKEIN_WIP: try_implicit_casts");
+            return type_caster_generic::try_implicit_casts(src, convert);
         }
         for (auto &cast : typeinfo->implicit_casts) {
             copyable_holder_caster sub_caster(*cast.first);
@@ -1029,11 +1029,11 @@ public:
             move_only_holder_caster<type, std::unique_ptr<type, deleter>>>(src, convert);
     }
 
-    bool load_value(value_and_holder &&v_h) {
+    void load_value(value_and_holder &&v_h) {
         if (typeinfo->default_holder) {
             sh_load_helper.loaded_v_h = v_h;
             sh_load_helper.loaded_v_h.type = get_type_info(typeid(type));
-            return true;
+            return;
         }
         throw std::runtime_error("BAKEIN_WIP: What is the best behavior here?");
     }
diff --git a/include/pybind11/detail/type_caster_base.h b/include/pybind11/detail/type_caster_base.h
index 27432ea10..779bb15a4 100644
--- a/include/pybind11/detail/type_caster_base.h
+++ b/include/pybind11/detail/type_caster_base.h
@@ -833,7 +833,8 @@ struct load_helper : value_and_holder_helper {
                                   shared_ptr_parent_life_support(parent.ptr()));
     }
 
-    std::shared_ptr<T> loaded_as_shared_ptr(handle responsible_parent = nullptr) const {
+    std::shared_ptr<T> loaded_as_shared_ptr(void *void_raw_ptr,
+                                            handle responsible_parent = nullptr) const {
         if (!have_holder()) {
             return nullptr;
         }
@@ -846,8 +847,7 @@ struct load_helper : value_and_holder_helper {
             }
             throw std::runtime_error("Non-owning holder (loaded_as_shared_ptr).");
         }
-        auto *void_raw_ptr = hld.template as_raw_ptr_unowned<void>();
-        auto *type_raw_ptr = convert_type(void_raw_ptr);
+        auto *type_raw_ptr = static_cast<T *>(void_raw_ptr);
         if (hld.pointee_depends_on_holder_owner) {
             auto *vptr_gd_ptr = std::get_deleter<pybindit::memory::guarded_delete>(hld.vptr);
             if (vptr_gd_ptr != nullptr) {