bpo-30459: Cast the result of PyList_SET_ITEM() to void (GH-19975)
Do the same for PyTuple_SET_ITEM().
diff --git a/Include/cpython/listobject.h b/Include/cpython/listobject.h
index e1b9462..e323915 100644
--- a/Include/cpython/listobject.h
+++ b/Include/cpython/listobject.h
@@ -30,5 +30,5 @@ PyAPI_FUNC(void) _PyList_DebugMallocStats(FILE *out);
#define _PyList_CAST(op) (assert(PyList_Check(op)), (PyListObject *)(op))
#define PyList_GET_ITEM(op, i) (_PyList_CAST(op)->ob_item[i])
-#define PyList_SET_ITEM(op, i, v) (_PyList_CAST(op)->ob_item[i] = (v))
+#define PyList_SET_ITEM(op, i, v) ((void)(_PyList_CAST(op)->ob_item[i] = (v)))
#define PyList_GET_SIZE(op) Py_SIZE(_PyList_CAST(op))
diff --git a/Include/cpython/tupleobject.h b/Include/cpython/tupleobject.h
index 51dcd42..7cada88 100644
--- a/Include/cpython/tupleobject.h
+++ b/Include/cpython/tupleobject.h
@@ -23,6 +23,6 @@ PyAPI_FUNC(void) _PyTuple_MaybeUntrack(PyObject *);
#define PyTuple_GET_ITEM(op, i) (_PyTuple_CAST(op)->ob_item[i])
/* Macro, *only* to be used to fill in brand new tuples */
-#define PyTuple_SET_ITEM(op, i, v) (_PyTuple_CAST(op)->ob_item[i] = v)
+#define PyTuple_SET_ITEM(op, i, v) ((void)(_PyTuple_CAST(op)->ob_item[i] = v))
PyAPI_FUNC(void) _PyTuple_DebugMallocStats(FILE *out);
diff --git a/Misc/NEWS.d/next/C API/2020-05-06-23-54-57.bpo-30459.N9_Jai.rst b/Misc/NEWS.d/next/C API/2020-05-06-23-54-57.bpo-30459.N9_Jai.rst
new file mode 100644
index 0000000..e3ee6dc
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2020-05-06-23-54-57.bpo-30459.N9_Jai.rst
@@ -0,0 +1,2 @@
+Cast the result of :c:func:`PyList_SET_ITEM` and :c:func:`PyTuple_SET_ITEM`
+to void.