SH, update shared_ptr copy tests

tests/test_class_sh_shared_ptr_copy.cpp

@@ -0,0 +1,51 @@
+#include "pybind11_tests.h"
+
+#include <pybind11/smart_holder.h>
+
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace pybind11_tests {
+namespace class_sh_shared_ptr_copy {
+
+template<int SerNo>
+struct Foo {
+    std::string mtxt;
+    Foo() : mtxt("DefaultConstructor") {}
+    Foo(const std::string &mtxt_) : mtxt(mtxt_) {}
+    Foo(const Foo &other) { mtxt = other.mtxt + "_CpCtor"; }
+    Foo(Foo &&other) { mtxt = other.mtxt + "_MvCtor"; }
+};
+
+using FooAVL = Foo<0>;
+using FooDEF = Foo<1>;
+
+} // namespace class_sh_shared_ptr_copy
+} // namespace pybind11_tests
+
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_shared_ptr_copy::FooAVL)
+
+namespace pybind11_tests {
+namespace class_sh_shared_ptr_copy {
+
+TEST_SUBMODULE(class_sh_shared_ptr_copy, m) {
+    namespace py = pybind11;
+
+    py::class_<FooAVL, PYBIND11_SH_AVL(FooAVL)>(m, "FooAVL");
+    py::class_<FooDEF, std::shared_ptr<FooDEF>>(m, "FooDEF");
+
+    m.def("test_avl", []() {
+        auto o = std::make_shared<FooAVL>("AVL");
+        auto l = py::list();
+        l.append(o);
+    });
+    m.def("test_def", []() {
+      auto o = std::make_shared<FooDEF>("DEF");
+      auto l = py::list();
+      l.append(o);
+    });
+}
+
+} // namespace class_sh_shared_ptr_copy
+} // namespace pybind11_tests