[ONNX] add 'Add' operator (#1192)

src/ngraph/frontend/onnx_import/CMakeLists.txt

@@ -39,6 +39,7 @@ add_library(onnx_import STATIC
     model.hpp
     node.cpp
     node.hpp
+    op/add.hpp
     ops_bridge.cpp
     ops_bridge.hpp
     tensor.hpp

src/ngraph/frontend/onnx_import/op/add.hpp

+/*******************************************************************************
+ * Copyright 2017-2018 Intel Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *******************************************************************************/
+
+#pragma once
+
+#include "ngraph/frontend/onnx_import/node.hpp"
+#include "ngraph/node_vector.hpp"
+#include "ngraph/op/add.hpp"
+
+namespace ngraph
+{
+    namespace onnx_import
+    {
+        namespace op
+        {
+            inline NodeVector add(const Node& node)
+            {
+                NodeVector ng_inputs{node.get_ng_inputs()};
+                return {std::make_shared<ngraph::op::Add>(ng_inputs.at(0), ng_inputs.at(1))};
+            }
+
+        } // namespace op
+
+    } // namespace onnx_import
+
+} // namespace ngrahp

src/ngraph/frontend/onnx_import/ops_bridge.cpp

@@ -17,6 +17,7 @@
 #include <algorithm>
 #include <functional>
 
+#include "ngraph/frontend/onnx_import/op/add.hpp"
 #include "ops_bridge.hpp"
 
 namespace ngraph
@@ -37,6 +38,7 @@ namespace ngraph
 
             } // namespace error
 
+            NodeVector add(const Node& node) { return op::add(node); }
             class ops_bridge
             {
             public:
@@ -59,7 +61,7 @@ namespace ngraph
                     return instance;
                 }
 
-                ops_bridge() {}
+                ops_bridge() { m_map.emplace("Add", std::bind(add, std::placeholders::_1)); }
                 NodeVector operator()(const Node& node) const
                 {
                     try