2 files changed, 12 insertions, 0 deletions
diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index 5baa69270e..d52722afb7 100644
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -970,6 +970,15 @@
 #define Q_DECL_ENUMERATOR_DEPRECATED Q_DECL_DEPRECATED
 #define Q_DECL_ENUMERATOR_DEPRECATED_X(x) Q_DECL_DEPRECATED_X(x)
 
+// [[nodiscard]] constructor
+#ifndef Q_NODISCARD_CTOR
+#  if __has_cpp_attribute(nodiscard) >= 201907L
+#    define Q_NODISCARD_CTOR [[nodiscard]]
+#  else
+#    define Q_NODISCARD_CTOR
+#  endif
+#endif
+
 /*
  * Fallback macros to certain compiler features
  */
diff --git a/src/corelib/thread/qmutex.h b/src/corelib/thread/qmutex.h
index af77f556fd..407473c799 100644
--- a/src/corelib/thread/qmutex.h
+++ b/src/corelib/thread/qmutex.h
@@ -231,6 +231,7 @@ template <typename Mutex>
 class [[nodiscard]] QMutexLocker
 {
 public:
+    Q_NODISCARD_CTOR
     inline explicit QMutexLocker(Mutex *mutex) QT_MUTEX_LOCK_NOEXCEPT
     {
         m_mutex = mutex;
@@ -240,6 +241,7 @@ public:
         }
     }
 
+    Q_NODISCARD_CTOR
     inline QMutexLocker(QMutexLocker &&other) noexcept
         : m_mutex(std::exchange(other.m_mutex, nullptr)),
           m_isLocked(std::exchange(other.m_isLocked, false))
@@ -326,6 +328,7 @@ template <typename Mutex>
 class [[nodiscard]] QMutexLocker
 {
 public:
+    Q_NODISCARD_CTOR
     inline explicit QMutexLocker(Mutex *) noexcept {}
     inline ~QMutexLocker() noexcept {}