From 567000e63d41d51f14bbcb4a91579ad680533205 Mon Sep 17 00:00:00 2001
From: Xuehai Pan <XuehaiPan@pku.edu.cn>
Date: Wed, 9 Oct 2024 15:46:43 +0800
Subject: [PATCH] feat: allow annotate methods with `pos_only` when only have
 the `self` argument

---
 include/pybind11/pybind11.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h
index 2527d25faf..fc68b5b091 100644
--- a/include/pybind11/pybind11.h
+++ b/include/pybind11/pybind11.h
@@ -300,10 +300,12 @@ class cpp_function : public function {
         {
             constexpr bool has_kw_only_args = any_of<std::is_same<kw_only, Extra>...>::value,
                            has_pos_only_args = any_of<std::is_same<pos_only, Extra>...>::value,
-                           has_arg_annotations = any_of<is_keyword<Extra>...>::value;
+                           has_arg_annotations = any_of<is_keyword<Extra>...>::value,
+                           has_is_method = any_of<std::is_same<is_method, Extra>...>::value;
             static_assert(has_arg_annotations || !has_kw_only_args,
                           "py::kw_only requires the use of argument annotations");
-            static_assert(has_arg_annotations || !has_pos_only_args,
+            static_assert(has_arg_annotations || !has_pos_only_args
+                              || (has_is_method /* method has at least one argument `self` */),
                           "py::pos_only requires the use of argument annotations (for docstrings "
                           "and aligning the annotations to the argument)");