Make QtConcurrent docs more readable

- Replaced 'auto' keyword in function signatures by the actual return
  type.

- Fixed signatures to not include enable_if statements.

Change-Id: I7292e8e506fd50d22974a86448fa4e85e8f08dfb
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Andreas Buhr <andreas.buhr@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

3 files changed, 125 insertions, 6 deletions

diff --git a/src/concurrent/qtconcurrentfilter.h b/src/concurrent/qtconcurrentfilter.h
index 8a17487466..0552b8c0e3 100644
--- a/src/concurrent/qtconcurrentfilter.h
+++ b/src/concurrent/qtconcurrentfilter.h
@@ -98,9 +98,14 @@ QFuture<ResultType> filteredReduced(Sequence &&sequence,
             QThreadPool::globalInstance(), std::forward<Sequence>(sequence), keep, reduce, options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> filteredReduced(QThreadPool *pool,
                                     Sequence &&sequence,
                                     KeepFunctor keep,
@@ -114,9 +119,14 @@ QFuture<ResultType> filteredReduced(QThreadPool *pool,
             ResultType(std::forward<InitialValueType>(initialValue)), options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> filteredReduced(Sequence &&sequence,
                                     KeepFunctor keep,
                                     ReduceFunctor reduce,
@@ -214,9 +224,14 @@ QFuture<ResultType> filteredReduced(Iterator begin,
            options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> filteredReduced(QThreadPool *pool,
                                     Iterator begin,
                                     Iterator end,
@@ -230,9 +245,14 @@ QFuture<ResultType> filteredReduced(QThreadPool *pool,
         ResultType(std::forward<InitialValueType>(initialValue)), options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> filteredReduced(Iterator begin,
                                     Iterator end,
                                     KeepFunctor keep,
@@ -380,9 +400,14 @@ ResultType blockingFilteredReduced(Sequence &&sequence,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingFilteredReduced(QThreadPool *pool,
                                    Sequence &&sequence,
                                    KeepFunctor keep,
@@ -397,9 +422,14 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingFilteredReduced(Sequence &&sequence,
                                    KeepFunctor keep,
                                    ReduceFunctor reduce,
@@ -505,9 +535,14 @@ ResultType blockingFilteredReduced(Iterator begin,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingFilteredReduced(QThreadPool *pool,
                                    Iterator begin,
                                    Iterator end,
@@ -522,9 +557,14 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingFilteredReduced(Iterator begin,
                                    Iterator end,
                                    KeepFunctor keep,
@@ -605,7 +645,7 @@ ResultType blockingFilteredReduced(Iterator begin,
 
 // blocking filtered() on sequences
 template <typename Sequence, typename KeepFunctor>
-auto blockingFiltered(QThreadPool *pool, Sequence &&sequence, KeepFunctor keep)
+std::decay_t<Sequence> blockingFiltered(QThreadPool *pool, Sequence &&sequence, KeepFunctor keep)
 {
     return blockingFilteredReduced<std::decay_t<Sequence>>(
             pool, std::forward<Sequence>(sequence), keep, QtPrivate::PushBackWrapper(),
@@ -613,7 +653,7 @@ auto blockingFiltered(QThreadPool *pool, Sequence &&sequence, KeepFunctor keep)
 }
 
 template <typename Sequence, typename KeepFunctor>
-auto blockingFiltered(Sequence &&sequence, KeepFunctor keep)
+std::decay_t<Sequence> blockingFiltered(Sequence &&sequence, KeepFunctor keep)
 {
     return blockingFilteredReduced<std::decay_t<Sequence>>(
             QThreadPool::globalInstance(), std::forward<Sequence>(sequence), keep,
diff --git a/src/concurrent/qtconcurrentmap.cpp b/src/concurrent/qtconcurrentmap.cpp
index 43313feeef..ec94975f38 100644
--- a/src/concurrent/qtconcurrentmap.cpp
+++ b/src/concurrent/qtconcurrentmap.cpp
@@ -588,7 +588,7 @@
 
     Calls \a function once for each item in \a sequence and returns an OutputSequence containing
     the results. All calls to \a function are invoked from the threads taken from the QThreadPool
-    \a pool. The type of the results will match the type returned my the MapFunctor.
+    \a pool. The type of the results will match the type returned by the MapFunctor.
 
     \note This function will block until all items in the sequence have been processed.
 
@@ -596,10 +596,10 @@
 */
 
 /*!
-  \fn template <typename OutputSequence, typename InputSequence, typename MapFunctor> OutputSequence QtConcurrent::blockingMapped(const InputSequence &&sequence, MapFunctor function)
+  \fn template <typename OutputSequence, typename InputSequence, typename MapFunctor> OutputSequence QtConcurrent::blockingMapped(InputSequence &&sequence, MapFunctor function)
 
   Calls \a function once for each item in \a sequence and returns an OutputSequence containing
-  the results. The type of the results will match the type returned my the MapFunctor.
+  the results. The type of the results will match the type returned by the MapFunctor.
 
   \note This function will block until all items in the sequence have been processed.
 
diff --git a/src/concurrent/qtconcurrentmap.h b/src/concurrent/qtconcurrentmap.h
index 2b475dced1..29ab364e77 100644
--- a/src/concurrent/qtconcurrentmap.h
+++ b/src/concurrent/qtconcurrentmap.h
@@ -105,9 +105,14 @@ QFuture<ResultType> mappedReduced(Sequence &&sequence,
         (QThreadPool::globalInstance(), std::forward<Sequence>(sequence), map, reduce, options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> mappedReduced(QThreadPool *pool,
                                   Sequence &&sequence,
                                   MapFunctor map,
@@ -120,10 +125,14 @@ QFuture<ResultType> mappedReduced(QThreadPool *pool,
             pool, std::forward<Sequence>(sequence), map, reduce,
             ResultType(std::forward<InitialValueType>(initialValue)), options);
 }
-
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> mappedReduced(Sequence &&sequence,
                                   MapFunctor map,
                                   ReduceFunctor reduce,
@@ -162,10 +171,15 @@ QFuture<ResultType> mappedReduced(
         (QThreadPool::globalInstance(), std::forward<Sequence>(sequence), map, reduce, options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename Sequence, typename MapFunctor, typename ReduceFunctor, typename ResultType,
+          typename InitialValueType>
+#else
 template <typename Sequence, typename MapFunctor, typename ReduceFunctor,
           typename ResultType = typename QtPrivate::ReduceResultType<ReduceFunctor>::ResultType,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> mappedReduced(QThreadPool *pool,
                                   Sequence &&sequence,
                                   MapFunctor map,
@@ -179,10 +193,15 @@ QFuture<ResultType> mappedReduced(QThreadPool *pool,
             ResultType(std::forward<InitialValueType>(initialValue)), options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename Sequence, typename MapFunctor, typename ReduceFunctor, typename ResultType,
+          typename InitialValueType>
+#else
 template <typename Sequence, typename MapFunctor, typename ReduceFunctor,
           typename ResultType = typename QtPrivate::ReduceResultType<ReduceFunctor>::ResultType,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> mappedReduced(Sequence &&sequence,
                                   MapFunctor map,
                                   ReduceFunctor reduce,
@@ -221,9 +240,14 @@ QFuture<ResultType> mappedReduced(Iterator begin,
         (QThreadPool::globalInstance(), begin, end, map, reduce, options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> mappedReduced(QThreadPool *pool,
                                   Iterator begin,
                                   Iterator end,
@@ -238,9 +262,14 @@ QFuture<ResultType> mappedReduced(QThreadPool *pool,
          ResultType(std::forward<InitialValueType>(initialValue)), options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> mappedReduced(Iterator begin,
                                   Iterator end,
                                   MapFunctor map,
@@ -281,10 +310,15 @@ QFuture<ResultType> mappedReduced(Iterator begin,
         (QThreadPool::globalInstance(), begin, end, map, reduce, options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename Iterator, typename MapFunctor, typename ReduceFunctor, typename ResultType,
+          typename InitialValueType>
+#else
 template <typename Iterator, typename MapFunctor, typename ReduceFunctor,
           typename ResultType = typename QtPrivate::ReduceResultType<ReduceFunctor>::ResultType,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> mappedReduced(QThreadPool *pool,
                                   Iterator begin,
                                   Iterator end,
@@ -299,10 +333,15 @@ QFuture<ResultType> mappedReduced(QThreadPool *pool,
          options);
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename Iterator, typename MapFunctor, typename ReduceFunctor, typename ResultType,
+          typename InitialValueType>
+#else
 template <typename Iterator, typename MapFunctor, typename ReduceFunctor,
           typename ResultType = typename QtPrivate::ReduceResultType<ReduceFunctor>::ResultType,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 QFuture<ResultType> mappedReduced(Iterator begin,
                                   Iterator end,
                                   MapFunctor map,
@@ -415,9 +454,14 @@ ResultType blockingMappedReduced(Sequence &&sequence,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingMappedReduced(QThreadPool *pool,
                                  Sequence &&sequence,
                                  MapFunctor map,
@@ -433,9 +477,14 @@ ResultType blockingMappedReduced(QThreadPool *pool,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingMappedReduced(Sequence &&sequence,
                                  MapFunctor map,
                                  ReduceFunctor reduce,
@@ -479,10 +528,15 @@ ResultType blockingMappedReduced(Sequence &&sequence,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename MapFunctor, typename ReduceFunctor, typename Sequence, typename ResultType,
+          typename InitialValueType>
+#else
 template <typename MapFunctor, typename ReduceFunctor, typename Sequence,
           typename ResultType = typename QtPrivate::ReduceResultType<ReduceFunctor>::ResultType,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingMappedReduced(QThreadPool *pool,
                                  Sequence &&sequence,
                                  MapFunctor map,
@@ -498,10 +552,15 @@ ResultType blockingMappedReduced(QThreadPool *pool,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename MapFunctor, typename ReduceFunctor, typename Sequence, typename ResultType,
+          typename InitialValueType>
+#else
 template <typename MapFunctor, typename ReduceFunctor, typename Sequence,
           typename ResultType = typename QtPrivate::ReduceResultType<ReduceFunctor>::ResultType,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingMappedReduced(Sequence &&sequence,
                                  MapFunctor map,
                                  ReduceFunctor reduce,
@@ -546,9 +605,14 @@ ResultType blockingMappedReduced(Iterator begin,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingMappedReduced(QThreadPool *pool,
                                  Iterator begin,
                                  Iterator end,
@@ -565,9 +629,14 @@ ResultType blockingMappedReduced(QThreadPool *pool,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
+          typename InitialValueType>
+#else
 template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingMappedReduced(Iterator begin,
                                  Iterator end,
                                  MapFunctor map,
@@ -614,10 +683,15 @@ ResultType blockingMappedReduced(Iterator begin,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename Iterator, typename MapFunctor, typename ReduceFunctor, typename ResultType,
+          typename InitialValueType>
+#else
 template <typename Iterator, typename MapFunctor, typename ReduceFunctor,
           typename ResultType = typename QtPrivate::ReduceResultType<ReduceFunctor>::ResultType,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingMappedReduced(QThreadPool *pool,
                                  Iterator begin,
                                  Iterator end,
@@ -634,10 +708,15 @@ ResultType blockingMappedReduced(QThreadPool *pool,
     return future.takeResult();
 }
 
+#ifdef Q_CLANG_QDOC
+template <typename Iterator, typename MapFunctor, typename ReduceFunctor, typename ResultType,
+          typename InitialValueType>
+#else
 template <typename Iterator, typename MapFunctor, typename ReduceFunctor,
           typename ResultType = typename QtPrivate::ReduceResultType<ReduceFunctor>::ResultType,
           typename InitialValueType,
           std::enable_if_t<std::is_convertible_v<InitialValueType, ResultType>, int> = 0>
+#endif
 ResultType blockingMappedReduced(Iterator begin,
                                  Iterator end,
                                  MapFunctor map,