feat(types): adds support for Never and NoReturn from python Typing (#5193)

* Adds support for Never and NoReturn

* lint

include/pybind11/typing.h

@@ -80,6 +80,13 @@ class Optional : public object {
     using object::object;
 };
 
+class NoReturn : public none {
+    using none::none;
+};
+
+class Never : public none {
+    using none::none;
+};
 #if defined(__cpp_nontype_template_parameter_class)
 template <size_t N>
 struct StringLiteral {
@@ -176,6 +183,15 @@ struct handle_type_name<typing::Optional<T>> {
     static constexpr auto name = const_name("Optional[") + make_caster<T>::name + const_name("]");
 };
 
+template <>
+struct handle_type_name<typing::NoReturn> {
+    static constexpr auto name = const_name("NoReturn");
+};
+
+template <>
+struct handle_type_name<typing::Never> {
+    static constexpr auto name = const_name("Never");
+};
 #if defined(__cpp_nontype_template_parameter_class)
 template <typing::StringLiteral... Literals>
 struct handle_type_name<typing::Literal<Literals...>> {

tests/test_pytypes.cpp

@@ -891,6 +891,9 @@ TEST_SUBMODULE(pytypes, m) {
               list.append(py::none());
               return list;
           });
+
+    m.def("annotate_no_return", []() -> py::typing::NoReturn { throw 0; });
+    m.def("annotate_never", []() -> py::typing::Never { throw 0; });
     m.def("annotate_optional_to_object",
           [](py::typing::Optional<int> &o) -> py::object { return o; });
 

tests/test_pytypes.py

@@ -991,6 +991,14 @@ def test_optional_annotations(doc):
     )
 
 
+def test_no_return_annotation(doc):
+    assert doc(m.annotate_no_return) == "annotate_no_return() -> NoReturn"
+
+
+def test_never_annotation(doc):
+    assert doc(m.annotate_never) == "annotate_never() -> Never"
+
+
 def test_optional_object_annotations(doc):
     assert (
         doc(m.annotate_optional_to_object)