Also use PyObjectTypeIsConvertibleToStdVector() in array_caster.

Author: rwgk

include/pybind11/stl.h

@@ -324,12 +324,8 @@ struct array_caster {
         return size == Size;
     }
 
-public:
-    bool load(handle src, bool convert) {
-        if (!isinstance<sequence>(src)) {
-            return false;
-        }
-        auto l = reinterpret_borrow<sequence>(src);
+    bool convert_elements(handle seq, bool convert) {
+        auto l = reinterpret_borrow<sequence>(seq);
         if (!require_size(l.size())) {
             return false;
         }
@@ -344,6 +340,25 @@ struct array_caster {
         return true;
     }
 
+public:
+    bool load(handle src, bool convert) {
+        if (!PyObjectTypeIsConvertibleToStdVector(src.ptr())) {
+            return false;
+        }
+        if (isinstance<sequence>(src)) {
+            return convert_elements(src, convert);
+        }
+        if (!convert) {
+            return false;
+        }
+        // Designed to be behavior-equivalent to passing tuple(src) from Python:
+        // The conversion to a tuple will first exhaust the generator object, to ensure that
+        // the generator is not left in an unpredictable (to the caller) partially-consumed
+        // state.
+        assert(isinstance<iterable>(src));
+        return convert_elements(tuple(reinterpret_borrow<iterable>(src)), convert);
+    }
+
     template <typename T>
     static handle cast(T &&src, return_value_policy policy, handle parent) {
         list l(src.size());

tests/test_stl.cpp

@@ -553,6 +553,8 @@ TEST_SUBMODULE(stl, m) {
     m.def("pass_std_vector_pair_int", [](const std::vector<std::pair<int, int>> &vec_pair_int) {
         return vec_pair_int.size();
     });
+    m.def("pass_std_array_int_2",
+          [](const std::array<int, 2> &arr_int) { return arr_int.size(); });
     m.def("pass_std_set_int", [](const std::set<int> &set_int) { return set_int.size(); });
     m.def("pass_std_map_int", [](const std::map<int, int> &map_int) { return map_int.size(); });
 }

tests/test_stl.py

@@ -381,15 +381,17 @@ def test_return_vector_bool_raw_ptr():
     assert len(v) == 4513
 
 
-def test_pass_std_vector_int():
-    fn = m.pass_std_vector_int
+@pytest.mark.parametrize("fn", [m.pass_std_vector_int, m.pass_std_array_int_2])
+def test_pass_std_vector_int(fn):
     assert fn([1, 2]) == 2
     assert fn((1, 2)) == 2
     assert fn({1, 2}) == 2
     assert fn({"x": 1, "y": 2}.values()) == 2
     assert fn({1: None, 2: None}.keys()) == 2
-    assert fn(i for i in range(3)) == 3
-    assert fn(map(lambda i: i, range(4))) == 4  # noqa: C417
+    assert fn(i for i in range(2)) == 2
+    assert fn(map(lambda i: i, range(2))) == 2  # noqa: C417
+    with pytest.raises(TypeError):
+        fn({1: 2, 3: 4})
     with pytest.raises(TypeError):
         fn({})