From 4f7b932fee79e8f446c435f59a67af0d8031c3af Mon Sep 17 00:00:00 2001
From: Yat Ho <lagoho7@gmail.com>
Date: Wed, 14 Jan 2026 05:02:50 +0800
Subject: [PATCH] build: correctly set MSVC `__cplusplus` (#8120)

* build: correctly set MSVC `__cplusplus`

* refactor: let utf8cpp infer `UTF_CPP_CPLUSPLUS`
---
 CMakeLists.txt           | 2 ++
 libtransmission/utils.cc | 1 -
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1143d71b1..165e464db 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -223,6 +223,8 @@ if(WIN32)
             set(CMAKE_${L}_FLAGS "${CMAKE_${L}_FLAGS} /utf-8")
             # Reduce noise (at least for now)
             set(CMAKE_${L}_FLAGS "${CMAKE_${L}_FLAGS} /wd4244 /wd4267")
+            # Correctly set __cplusplus macro value
+            set(CMAKE_${L}_FLAGS "${CMAKE_${L}_FLAGS} /Zc:__cplusplus")
             # Make caching-friendly (store debug info inside object files)
             foreach(T IN ITEMS ${CMAKE_CONFIGURATION_TYPES} ${CMAKE_BUILD_TYPE})
                 string(TOUPPER "${T}" T)
diff --git a/libtransmission/utils.cc b/libtransmission/utils.cc
index 81c2f356c..c85a2fd04 100644
--- a/libtransmission/utils.cc
+++ b/libtransmission/utils.cc
@@ -36,7 +36,6 @@
 #include <sys/stat.h> /* umask() */
 #endif
 
-#define UTF_CPP_CPLUSPLUS 201703L
 #include <utf8.h>
 
 #include <curl/curl.h>