QThread::create: move implementation out of line

Now that we accept STL datatypes in our ABI, expose a factory
function that takes a std::future<void>, and hide the QThread
subclass in our implementation. This also solves the problem
of a non-exported polymorphic class that would generate duplicate
vtables / typeinfo in all TUs.

Change-Id: I70a5c301e7c589de1a4a189db39b86b956d1ba0d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index 1ec626a53b..e3ba1e4449 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -925,6 +925,30 @@ bool QThread::isInterruptionRequested() const
     \sa start()
 */
 
+#ifdef QTHREAD_HAS_CREATE
+class QThreadCreateThread : public QThread
+{
+public:
+    explicit QThreadCreateThread(std::future<void> &&future)
+        : m_future(std::move(future))
+    {
+    }
+
+private:
+    void run() override
+    {
+        m_future.get();
+    }
+
+    std::future<void> m_future;
+};
+
+QThread *QThread::createThreadImpl(std::future<void> &&future)
+{
+    return new QThreadCreateThread(std::move(future));
+}
+#endif // QTHREAD_HAS_CREATE
+
 /*!
     \class QDaemonThread
     \since 5.5