fix issue taskflow#446 byy adding workround for visual studio 2017

qingfengxia · Nov 27, 2022 · ac8433e · ac8433e
1 parent a7bde2f
commit ac8433e
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Showing 4 changed files with 46 additions and 5 deletions.
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
@@ -23,7 +23,6 @@ list(APPEND TF_EXAMPLES
   text_pipeline
   taskflow_pipeline
   parallel_graph_pipeline
-  parallel_data_pipeline
   run 
   run_and_wait
   runtime
@@ -34,6 +33,14 @@ list(APPEND TF_EXAMPLES
   cancel_async
 )
 
+if (MSVC)
+    if(MSVC_VERSION VERSION_LESS 1920)
+        message("visual studio 2017 can not compile example: parallel_data_pipeline, skip it")
+    endif()
+else()
+    list(append TF_EXAMPLES  parallel_data_pipeline)
+endif()
+
 foreach(example IN LISTS TF_EXAMPLES)
   add_executable(${example} ${example}.cpp)
   target_link_libraries(

diff --git a/taskflow/core/executor.hpp b/taskflow/core/executor.hpp
@@ -766,6 +766,9 @@ class Executor {
     template <typename P>
     void _loop_until(Worker&, P&&);
 
+    template <typename F, bool IsVoidRet, typename... ArgsT>
+    auto _named_async_T(const std::string& name, F&& f, ArgsT&&... args);
+
     template <typename C, std::enable_if_t<is_cudaflow_task_v<C>, void>* = nullptr>
     void _invoke_cudaflow_task_entry(Node*, C&&);
 
@@ -842,9 +845,16 @@ inline Worker* Executor::_this_worker() {
   return itr == _wids.end() ? nullptr : &_workers[itr->second];
 }
 
-// Function: named_async
 template <typename F, typename... ArgsT>
 auto Executor::named_async(const std::string& name, F&& f, ArgsT&&... args) {
+    // workaround for visual studio 2017, see details in issues#446
+    return _named_async_T<F, std::is_same_v<std::invoke_result_t<F, ArgsT...>, void>, ArgsT...>
+        (name, std::forward<F>(f), std::forward<ArgsT>(args)...);
+}
+
+// Function: named_async
+template <typename F, bool IsVoidRet, typename... ArgsT>
+auto Executor::_named_async_T(const std::string& name, F&& f, ArgsT&&... args) {
 
   _increment_topology();
 
@@ -861,7 +871,7 @@ auto Executor::named_async(const std::string& name, F&& f, ArgsT&&... args) {
     std::in_place_type_t<Node::Async>{},
     [p=make_moc(std::move(p)), f=std::forward<F>(f), args...]
     (bool cancel) mutable {
-      if constexpr(std::is_same_v<R, void>) {
+      if constexpr(IsVoidRet) {
         if(!cancel) {
           f(args...);
         }
@@ -2040,6 +2050,20 @@ auto Subflow::named_async(const std::string& name, F&& f, ArgsT&&... args) {
 // Function: _named_async
 template <typename F, typename... ArgsT>
 auto Subflow::_named_async(
+    Worker& w,
+    const std::string& name,
+    F&& f,
+    ArgsT&&... args
+) {
+    // workaround for visual studio 2017, see details in discussion in issues#446
+    // by adding an extra function call wrapper, because type_trait not working in lambda
+    return _named_async_T<F, std::is_same_v<std::invoke_result_t<F, ArgsT...>, void>, ArgsT...>
+        (w, name, std::forward<F>(f), std::forward<ArgsT>(args)...);
+}
+
+// workaround 
+template <typename F, bool IsVoidRet, typename... ArgsT>
+auto Subflow::_named_async_T(
   Worker& w,
   const std::string& name,
   F&& f,
@@ -2061,7 +2085,7 @@ auto Subflow::_named_async(
     std::in_place_type_t<Node::Async>{},
     [p=make_moc(std::move(p)), f=std::forward<F>(f), args...]
     (bool cancel) mutable {
-      if constexpr(std::is_same_v<R, void>) {
+      if constexpr(IsVoidRet) {
         if(!cancel) {
           f(args...);
         }

diff --git a/taskflow/core/flow_builder.hpp b/taskflow/core/flow_builder.hpp
@@ -1096,6 +1096,9 @@ class Subflow : public FlowBuilder {
     template <typename F, typename... ArgsT>
     auto _named_async(Worker& w, const std::string& name, F&& f, ArgsT&&... args);
 
+    template <typename F, bool IsVoidRet, typename... ArgsT>
+    auto _named_async_T(Worker& w, const std::string& name, F&& f, ArgsT&&... args);
+
     template <typename F, typename... ArgsT>
     void _named_silent_async(Worker& w, const std::string& name, F&& f, ArgsT&&... args);
 };

diff --git a/unittests/CMakeLists.txt b/unittests/CMakeLists.txt
@@ -21,10 +21,17 @@ list(APPEND TF_UNITTESTS
   pipelines
   scalable_pipelines
   runtimes
-  data_pipelines
   workers
 )
 
+if (MSVC)
+    if(MSVC_VERSION VERSION_LESS 1920)
+        message("visual studio 2017 can not compile unittest: data_pipelines, skip it")
+    endif()
+else()
+    list(append TF_UNITTESTS data_pipelines)
+endif()
+
 foreach(unittest IN LISTS TF_UNITTESTS)
   add_executable(${unittest} ${unittest}.cpp)
   target_link_libraries(${unittest} ${PROJECT_NAME} tf::default_settings)