Mark add_handler std::function argument as requiring __cdecl to guard against compiler options

Author: ras0219-msft

Release/include/cpprest/http_client.h

@@ -442,7 +442,7 @@ class http_client
     /// Adds an HTTP pipeline stage to the client.
     /// </summary>
     /// <param name="handler">A function object representing the pipeline stage.</param>
-    _ASYNCRTIMP void add_handler(const std::function<pplx::task<http_response>(http_request, std::shared_ptr<http::http_pipeline_stage>)> &handler);
+    _ASYNCRTIMP void add_handler(const std::function<pplx::task<http_response> __cdecl(http_request, std::shared_ptr<http::http_pipeline_stage>)> &handler);
 
 
     /// <summary>

Release/src/http/client/http_client.cpp

@@ -331,12 +331,12 @@ class http_pipeline
     pplx::extensibility::recursive_lock_t m_lock;
 };
 
-void http_client::add_handler(const std::function<pplx::task<http_response>(http_request, std::shared_ptr<http::http_pipeline_stage>)> &handler)
+void http_client::add_handler(const std::function<pplx::task<http_response> __cdecl(http_request, std::shared_ptr<http::http_pipeline_stage>)> &handler)
 {
     class function_pipeline_wrapper : public http::http_pipeline_stage
     {
     public:
-        function_pipeline_wrapper(const std::function<pplx::task<http_response>(http_request, std::shared_ptr<http::http_pipeline_stage>)> &handler) : m_handler(handler)
+        function_pipeline_wrapper(const std::function<pplx::task<http_response> __cdecl(http_request, std::shared_ptr<http::http_pipeline_stage>)> &handler) : m_handler(handler)
         {
         }