Introduce Worker::hasThread() replacing bool operator

Author: daschuer

src/analyzer/trackanalysisscheduler.cpp

@@ -228,7 +228,7 @@ void TrackAnalysisScheduler::onWorkerThreadProgress(
         DEBUG_ASSERT(!trackId.isValid());
         DEBUG_ASSERT(analyzerProgress == kAnalyzerProgressUnknown);
         worker.onThreadExit();
-        DEBUG_ASSERT(!worker);
+        DEBUG_ASSERT(!worker.hasThread());
         break;
     default:
         DEBUG_ASSERT(!"Unhandled signal from worker thread");

src/analyzer/trackanalysisscheduler.h

@@ -87,7 +87,7 @@ class TrackAnalysisScheduler : public QObject {
         Worker(const Worker&) = delete;
         Worker(Worker&&) = default;
 
-        operator bool() const {
+        bool hasThread() const {
             return static_cast<bool>(m_pThread);
         }