From a3f5e7b8e3deb783b5aed29dcf935a2a47850a8d Mon Sep 17 00:00:00 2001
From: Pierre Yager <pierre.yager@crisalid.com>
Date: Tue, 18 Nov 2025 18:02:31 +0100
Subject: [PATCH] Fix to make czmq/zyre build in MSVC 2022 when C version is
 <23

---
 include/czmq_prelude.h | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/czmq_prelude.h b/include/czmq_prelude.h
index c885c9639..d6c86a185 100644
--- a/include/czmq_prelude.h
+++ b/include/czmq_prelude.h
@@ -530,15 +530,16 @@ typedef struct {
 
 
 // Fallback for booleans for pre-C23 C and MSVC builds
-#if defined(__STDC_VERSION__) && __STDC_VERSION__ < 202311L
-#   if (defined (_MSC_VER))
-#       if (!defined (__cplusplus) && (!defined (true)))
-#           define true 1
-#           define false 0
-            typedef char bool;
-#       endif
+#if !defined(__cplusplus) && !defined(__bool_true_false_are_defined)
+#   if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L
+#      include <stdbool.h>
+#   elif defined(_MSC_VER)
+       typedef char bool;
+#      define true  1
+#      define false 0
+#      define __bool_true_false_are_defined 1
 #   else
-#       include <stdbool.h>
+#      include <stdbool.h>
 #   endif
 #endif