CMake: remove check for cxx11_future

Everyone must have this by now. This test was 1193 ms of CMake time.

Since this was a PUBLIC feature, I've left it around with a constant
condition.

Change-Id: Ifbf974a4d10745b099b1fffd177754538bbff245
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

3 files changed, 3 insertions, 34 deletions

diff --git a/src/corelib/configure.cmake b/src/corelib/configure.cmake
index 6e8de89099..eca3b01886 100644
--- a/src/corelib/configure.cmake
+++ b/src/corelib/configure.cmake
@@ -137,27 +137,6 @@ int pipes[2];
 }
 ")
 
-# cxx11_future
-if (UNIX AND NOT ANDROID AND NOT QNX AND NOT INTEGRITY)
-    set(cxx11_future_TEST_LIBRARIES pthread)
-endif()
-qt_config_compile_test(cxx11_future
-    LABEL "C++11 <future>"
-    LIBRARIES
-     "${cxx11_future_TEST_LIBRARIES}"
-    CODE
-"#include <future>
-
-int main(void)
-{
-    /* BEGIN TEST: */
-std::future<int> f = std::async([]() { return 42; });
-(void)f.get();
-    /* END TEST: */
-    return 0;
-}
-")
-
 # cxx17_filesystem
 qt_config_compile_test(cxx17_filesystem
     LABEL "C++17 <filesystem>"
@@ -565,7 +544,7 @@ qt_feature("system-doubleconversion" PRIVATE
 )
 qt_feature("cxx11_future" PUBLIC
     LABEL "C++11 <future>"
-    CONDITION TEST_cxx11_future
+    CONDITION ON
 )
 qt_feature("cxx17_filesystem" PUBLIC
     LABEL "C++17 <filesystem>"
diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index 61369420d1..111c6a93d5 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -1201,7 +1201,6 @@ bool QThread::isInterruptionRequested() const
     \sa start()
 */
 
-#if QT_CONFIG(cxx11_future)
 class QThreadCreateThread : public QThread
 {
 public:
@@ -1230,7 +1229,6 @@ QThread *QThread::createThreadImpl(std::future<void> &&future)
 {
     return new QThreadCreateThread(std::move(future));
 }
-#endif // QT_CONFIG(cxx11_future)
 
 /*!
     \class QDaemonThread
diff --git a/src/corelib/thread/qthread.h b/src/corelib/thread/qthread.h
index 40f363ee5a..32a0bb703e 100644
--- a/src/corelib/thread/qthread.h
+++ b/src/corelib/thread/qthread.h
@@ -9,10 +9,8 @@
 #include <QtCore/qdeadlinetimer.h>
 
 // For QThread::create
-#if QT_CONFIG(cxx11_future)
-#  include <future> // for std::async
-#  include <functional> // for std::invoke; no guard needed as it's a C++98 header
-#endif
+#include <future> // for std::async
+#include <functional> // for std::invoke; no guard needed as it's a C++98 header
 // internal compiler error with mingw 8.1
 #if defined(Q_CC_MSVC) && defined(Q_PROCESSOR_X86)
 #include <intrin.h>
@@ -70,10 +68,8 @@ public:
     bool event(QEvent *event) override;
     int loopLevel() const;
 
-#if QT_CONFIG(cxx11_future) || defined(Q_QDOC)
     template <typename Function, typename... Args>
     [[nodiscard]] static QThread *create(Function &&f, Args &&... args);
-#endif
 
 public Q_SLOTS:
     void start(Priority = InheritPriority);
@@ -112,16 +108,13 @@ private:
     Q_DECLARE_PRIVATE(QThread)
     friend class QEventLoopLocker;
 
-#if QT_CONFIG(cxx11_future)
     [[nodiscard]] static QThread *createThreadImpl(std::future<void> &&future);
-#endif
     static Qt::HANDLE currentThreadIdImpl() noexcept Q_DECL_PURE_FUNCTION;
 
     friend class QCoreApplication;
     friend class QThreadData;
 };
 
-#if QT_CONFIG(cxx11_future)
 template <typename Function, typename... Args>
 QThread *QThread::create(Function &&f, Args &&... args)
 {
@@ -136,7 +129,6 @@ QThread *QThread::create(Function &&f, Args &&... args)
                                        std::move(threadFunction),
                                        std::forward<Args>(args)...));
 }
-#endif // QT_CONFIG(cxx11_future)
 
 /*
     On architectures and platforms we know, interpret the thread control