Demonstrate issue from #2786

Author: YannickJadoul

tests/test_pytypes.cpp

@@ -270,6 +270,7 @@ TEST_SUBMODULE(pytypes, m) {
         throw std::runtime_error("Invalid type");
     });
 
+    // test_implicit_casting
     m.def("get_implicit_casting", []() {
         py::dict d;
         d["char*_i1"] = "abc";
@@ -307,6 +308,10 @@ TEST_SUBMODULE(pytypes, m) {
         );
     });
 
+    // (see also test_builtin_casters)
+    m.def("implicitly_cast_to_int32", [](py::int_ value) { return int32_t{value}; });
+    m.def("implicitly_cast_to_uint32", [](py::int_ value) { return uint32_t{value}; });
+
     // test_print
     m.def("print_function", []() {
         py::print("Hello, World!");

tests/test_pytypes.py

@@ -331,6 +331,14 @@ def test_implicit_casting():
     }
     assert z["l"] == [3, 6, 9, 12, 15]
 
+    assert m.implicitly_cast_to_int32(42) == 42
+    assert m.implicitly_cast_to_int32(2 ** 31 - 1) == 2 ** 31 - 1
+    assert m.implicitly_cast_to_int32(2 ** 31)
+
+    assert m.implicitly_cast_to_uint32(42) == 42
+    assert m.implicitly_cast_to_uint32(2 ** 32 - 1) == 2 ** 32 - 1
+    assert m.implicitly_cast_to_uint32(2 ** 32)
+
 
 def test_print(capture):
     with capture: