From 82455a41fdc9cabf6a0eeba2071dc8a0c8cac4c1 Mon Sep 17 00:00:00 2001
From: Aaron Gokaslan <skylion.aaron@gmail.com>
Date: Sun, 24 Apr 2022 14:46:39 -0400
Subject: [PATCH] Minor opt to cache tuple casting (#3894)

---
 include/pybind11/numpy.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/pybind11/numpy.h b/include/pybind11/numpy.h
index 2713e13a..b8ba2259 100644
--- a/include/pybind11/numpy.h
+++ b/include/pybind11/numpy.h
@@ -647,8 +647,9 @@ private:
         for (auto field : attr("fields").attr("items")()) {
             auto spec = field.cast<tuple>();
             auto name = spec[0].cast<pybind11::str>();
-            auto format = spec[1].cast<tuple>()[0].cast<dtype>();
-            auto offset = spec[1].cast<tuple>()[1].cast<pybind11::int_>();
+            auto spec_fo = spec[1].cast<tuple>();
+            auto format = spec_fo[0].cast<dtype>();
+            auto offset = spec_fo[1].cast<pybind11::int_>();
             if ((len(name) == 0u) && format.kind() == 'V') {
                 continue;
             }