From 863833378438a3f14927f573e7e74a99d3fc5afc Mon Sep 17 00:00:00 2001
From: Michael Chirico <chiricom@google.com>
Date: Tue, 29 Apr 2025 14:38:27 -0700
Subject: [PATCH 1/3] Correct header for size_t

---
 inst/include/cpp11/named_arg.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/inst/include/cpp11/named_arg.hpp b/inst/include/cpp11/named_arg.hpp
index df7ba935..3590b033 100644
--- a/inst/include/cpp11/named_arg.hpp
+++ b/inst/include/cpp11/named_arg.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <stddef.h>  // for size_t
+#include <cstddef>  // for size_t
 
 #include <initializer_list>  // for initializer_list
 

From 68a29243dfe1cce979f407dc6c3581792b57d459 Mon Sep 17 00:00:00 2001
From: Davis Vaughan <davis@posit.co>
Date: Fri, 16 Jan 2026 21:21:05 -0500
Subject: [PATCH 2/3] Be consistent with using C++ specific C compat headers

---
 inst/include/cpp11/function.hpp | 3 +--
 inst/include/cpp11/r_vector.hpp | 3 +--
 inst/include/cpp11/sexp.hpp     | 5 ++---
 3 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/inst/include/cpp11/function.hpp b/inst/include/cpp11/function.hpp
index 42fbdcf6..cc5af071 100644
--- a/inst/include/cpp11/function.hpp
+++ b/inst/include/cpp11/function.hpp
@@ -1,8 +1,7 @@
 #pragma once
 
-#include <string.h>  // for strcmp
-
 #include <cstdio>   // for snprintf
+#include <cstring>  // for strcmp
 #include <string>   // for string, basic_string
 #include <utility>  // for forward
 
diff --git a/inst/include/cpp11/r_vector.hpp b/inst/include/cpp11/r_vector.hpp
index 1131b554..317b16f1 100644
--- a/inst/include/cpp11/r_vector.hpp
+++ b/inst/include/cpp11/r_vector.hpp
@@ -1,9 +1,8 @@
 #pragma once
 
-#include <stddef.h>  // for ptrdiff_t, size_t
-
 #include <algorithm>         // for max
 #include <array>             // for array
+#include <cstddef>           // for ptrdiff_t, size_t
 #include <cstdio>            // for snprintf
 #include <cstring>           // for memcpy
 #include <exception>         // for exception
diff --git a/inst/include/cpp11/sexp.hpp b/inst/include/cpp11/sexp.hpp
index 74205e69..34f7e2b8 100644
--- a/inst/include/cpp11/sexp.hpp
+++ b/inst/include/cpp11/sexp.hpp
@@ -1,8 +1,7 @@
 #pragma once
 
-#include <stddef.h>  // for size_t
-
-#include <string>  // for string, basic_string
+#include <cstddef>  // for size_t
+#include <string>   // for string, basic_string
 
 #include "cpp11/R.hpp"                // for SEXP, SEXPREC, REAL_ELT, R_NilV...
 #include "cpp11/attribute_proxy.hpp"  // for attribute_proxy

From beb9e4befa5dcd83c6e83dbc7308a4e030976620 Mon Sep 17 00:00:00 2001
From: Davis Vaughan <davis@posit.co>
Date: Fri, 16 Jan 2026 21:23:37 -0500
Subject: [PATCH 3/3] NEWS bullet

---
 NEWS.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/NEWS.md b/NEWS.md
index 5b16fd54..36f15bba 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,7 @@
 # cpp11 (development version)
 
+* Improved hygiene around using C++ specific C compatibility headers (i.e. by using `<cstring>` rather than `<string.h>` and `<cstddef>` rather than `<stddef.h>`) (#454, @MichaelChirico).
+
 * Fixed an rchk issue related to `std::initializer_list<named_arg>` (#457, @pachadotdev).
 
 # cpp11 0.5.2