From 93bea3f8e4fedc0f63e4f7564662fe9036a99ee1 Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Thu, 22 Jan 2026 22:06:43 +0000
Subject: [PATCH] Fix `-Wunused-private-field` when building with clang-cl on
 Windows

---
 cpp-subprocess/subprocess.hpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/cpp-subprocess/subprocess.hpp b/cpp-subprocess/subprocess.hpp
index 63fd762..da2d950 100644
--- a/cpp-subprocess/subprocess.hpp
+++ b/cpp-subprocess/subprocess.hpp
@@ -1169,6 +1169,7 @@ struct ArgumentDeducer
   Popen* popen_ = nullptr;
 };
 
+#ifndef __USING_WINDOWS__
 /*!
  * A helper class to Popen.
  * This takes care of all the fork-exec logic
@@ -1190,6 +1191,7 @@ class Child
   Popen* parent_ = nullptr;
   int err_wr_pipe_ = -1;
 };
+#endif
 
 // Fwd Decl.
 class Streams;
@@ -1377,7 +1379,9 @@ class Popen
 {
 public:
   friend struct detail::ArgumentDeducer;
+#ifndef __USING_WINDOWS__
   friend class detail::Child;
+#endif
 
   template <typename... Args>
   Popen(const std::string& cmd_args, Args&& ...args):
@@ -1891,8 +1895,8 @@ namespace detail {
   }
 
 
-  inline void Child::execute_child() {
 #ifndef __USING_WINDOWS__
+  inline void Child::execute_child() {
     int sys_ret = -1;
     auto& stream = parent_->stream_;
 
@@ -1985,8 +1989,8 @@ namespace detail {
     // Calling application would not get this
     // exit failure
     _exit (EXIT_FAILURE);
-#endif
   }
+#endif
 
 
   inline void Streams::setup_comm_channels()