Support arbitrary type in item accessor's subscript operator

include/pybind11/pytypes.h

@@ -92,11 +92,8 @@ public:
         subclass causes a corresponding call to ``__getitem__``. Assigning a `handle`
         or `object` subclass causes a call to ``__setitem__``.
     \endrst */
-    item_accessor operator[](handle key) const;
-    /// See above (the only difference is that the key's reference is stolen)
-    item_accessor operator[](object &&key) const;
-    /// See above (the only difference is that the key is provided as a string literal)
-    item_accessor operator[](const char *key) const;
+    template <typename T>
+    item_accessor operator[](T &&key) const;
 
     /** \rst
         Return an internal functor to access the object's attributes. Casting the
@@ -2270,16 +2267,9 @@ iterator object_api<D>::end() const {
     return iterator::sentinel();
 }
 template <typename D>
-item_accessor object_api<D>::operator[](handle key) const {
-    return {derived(), reinterpret_borrow<object>(key)};
-}
-template <typename D>
-item_accessor object_api<D>::operator[](object &&key) const {
-    return {derived(), std::move(key)};
-}
-template <typename D>
-item_accessor object_api<D>::operator[](const char *key) const {
-    return {derived(), pybind11::str(key)};
+template <typename T>
+item_accessor object_api<D>::operator[](T &&key) const {
+    return {derived(), reinterpret_borrow<object>(detail::object_or_cast(std::forward<T>(key)))};
 }
 template <typename D>
 obj_attr_accessor object_api<D>::attr(handle key) const {

tests/test_pytypes.cpp

@@ -126,6 +126,10 @@ TEST_SUBMODULE(pytypes, m) {
     m.def("tuple_ssize_t", []() { return py::tuple{(py::ssize_t) 0}; });
     m.def("tuple_size_t", []() { return py::tuple{(py::size_t) 0}; });
     m.def("get_tuple", []() { return py::make_tuple(42, py::none(), "spam"); });
+    m.def("access_tuple_with_int_index", []() {
+        py::object tpl = py::make_tuple(1, 2);
+        return tpl[1];
+    });
 
     // test_simple_namespace
     m.def("get_simple_namespace", []() {

tests/test_pytypes.py

@@ -152,6 +152,7 @@ def test_tuple():
     assert m.tuple_ssize_t() == ()
     assert m.tuple_size_t() == ()
     assert m.get_tuple() == (42, None, "spam")
+    assert m.access_tuple_with_int_index() == (2)
 
 
 def test_simple_namespace():