Add copy_with_new_args primitive for subgraph cloning (#225)

examples/Makefile

-
-# Copyright 2017 Nervana Systems Inc.
-# 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.
-NGRAPH_DIST_DIR = ${HOME}/ngraph_dist
-CXXFLAGS += -std=c++11
-CPPFLAGS += -I $(NGRAPH_DIST_DIR)
-LDFLAGS = -L $(NGRAPH_DIST_DIR)
-OBJ = main.o
-
-%.o: %.cpp $(DEPS)
-	$(CXX) -c -o $@ $< $(CXXFLAGS) $(CPPFLAGS)
-
-ngraph-test: $(OBJ) 
-	$(CXX) -o $@ $(OBJ) $(LDFLAGS) -lngraph
-
-.PHONY: clean
-
-clean:
-	rm -f $(OBJ) ngraph-test

examples/main.cpp

-// ----------------------------------------------------------------------------
-// Copyright 2017 Nervana Systems Inc.
-// 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
-// ----------------------------------------------------------------------------
-
-#include <stdio.h>
-#include "ngraph/ngraph.hpp"
-#include "ngraph/ops/dot.hpp"
-
-using namespace std;
-using namespace ngraph;
-
-int main(int argc, char** argv)
-{
-    printf( "Building graph\n" );
-
-    // Function with 4 parameters
-    auto arg0        = op::parameter(element::Float::type, {7, 3});
-    auto arg1        = op::parameter(element::Float::type, {3});
-    auto arg2        = op::parameter(element::Float::type, {32, 7});
-    auto arg3        = op::parameter(element::Float::type, {32, 7});
-    auto broadcast_1 = op::broadcast(arg3, {10, 32, 7}, {0});
-    auto dot         = op::dot(arg2, arg0);
-    
-    auto cluster_0 = op::function(dot, {arg0, arg1, arg2, arg3});
-    auto result = cluster_0->result();
-
-    printf( "Finished\n" );
-    
-}
\ No newline at end of file

src/ngraph/node.hpp

@@ -117,8 +117,12 @@ namespace ngraph
         std::shared_ptr<Node> backprop_node(const std::shared_ptr<Node>& x,
                                             const std::shared_ptr<Node>& c);
 
-        /// Returns the shape if this node has tensor type, othetwise error.
+        /// Returns the shape if this node has tensor type, otherwise an ngraph-error is thrown.
         const Shape& get_shape() const { return m_value_type->get_shape(); }
+        const element::Type& get_element_type() const { return m_value_type->get_element_type(); }
+        virtual std::shared_ptr<Node>
+            copy_with_new_args(const std::vector<std::shared_ptr<Node>>& new_args) const = 0;
+
     protected:
         Nodes m_arguments;
         std::shared_ptr<const ValueType> m_value_type;

src/ngraph/ops/abs.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <memory>
+
 #include "ngraph/ops/op.hpp"
 
 namespace ngraph
@@ -50,6 +52,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Abs>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Abs"; }
         };
     }

src/ngraph/ops/acos.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <memory>
+
 #include "ngraph/ops/op.hpp"
 
 namespace ngraph
@@ -50,6 +52,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Acos>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Acos"; }
         };
     }

src/ngraph/ops/add.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <memory>
+
 #include "ngraph/ops/op.hpp"
 
 namespace ngraph
@@ -51,6 +53,15 @@ namespace ngraph
                 : BinaryElementwiseArithmetic(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Add>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Add"; }
         protected:
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,

src/ngraph/ops/asin.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <memory>
+
 #include "ngraph/ops/op.hpp"
 
 namespace ngraph
@@ -50,6 +52,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Asin>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Asin"; }
         };
     }

src/ngraph/ops/atan.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <memory>
+
 #include "ngraph/ops/op.hpp"
 
 namespace ngraph
@@ -50,6 +52,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Atan>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Atan"; }
         };
     }

src/ngraph/ops/broadcast.hpp

@@ -74,12 +74,20 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Broadcast>(new_args.at(0), m_shape, m_broadcast_axes);
+            }
+
             virtual std::string description() const override { return "Broadcast"; }
             virtual void propagate_types() override;
 
             /// \return An set containing the indices of the broadcast axes (0-based).
             const AxisSet& get_broadcast_axes() const { return m_broadcast_axes; }
-        protected:
+            const Shape& get_broadcast_shape() const { return m_shape; }
         protected:
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,
                                            const std::shared_ptr<Node>& delta) override;

src/ngraph/ops/ceiling.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Ceiling>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Ceiling"; }
         };
     }

src/ngraph/ops/concatenate.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <memory>
+
 #include "ngraph/ops/op.hpp"
 
 namespace ngraph
@@ -74,6 +76,12 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                return std::make_shared<Concat>(new_args, m_concatenation_axis);
+            }
+
             virtual std::string description() const override { return "Concatenate"; }
             virtual void propagate_types() override;
 

src/ngraph/ops/constant.hpp

@@ -82,12 +82,20 @@ namespace ngraph
             /// \param value The value of the tensor constant.
             ParameterizedConstant(
                 const Shape& shape,
-                typename std::shared_ptr<ngraph::runtime::ParameterizedTensorView<T>>& value)
+                const typename std::shared_ptr<ngraph::runtime::ParameterizedTensorView<T>>& value)
                 : ConstantBase(std::make_shared<TensorViewType>(T::element_type(), shape))
                 , m_value(value)
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 0)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<ParameterizedConstant<T>>(get_shape(), m_value);
+            }
+
             virtual std::string description() const override { return "ParameterizedConstant"; }
             virtual std::string get_node_id() const override
             {
@@ -103,7 +111,7 @@ namespace ngraph
             }
 
         protected:
-            std::shared_ptr<ngraph::runtime::ParameterizedTensorView<T>> m_value;
+            const std::shared_ptr<ngraph::runtime::ParameterizedTensorView<T>> m_value;
         };
 
         /// \brief A 32-bit floating-point tensor constant.
@@ -171,6 +179,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 0)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Constant>(get_element_type(), get_shape(), m_value_strings);
+            }
+
             virtual std::string description() const override { return "Constant"; }
             virtual std::string get_node_id() const override
             {

src/ngraph/ops/convert.hpp

@@ -61,8 +61,17 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Convert>(new_args.at(0), m_element_type);
+            }
+
             virtual const element::Type&
                 propagate_element_types(const element::Type& arg_element_type) const override;
+            const element::Type& get_convert_element_type() const { return m_element_type; }
             virtual std::string description() const override { return "Convert"; }
         protected:
             const ngraph::element::Type& m_element_type;

src/ngraph/ops/cos.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Cos>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Cos"; }
         };
     }

src/ngraph/ops/cosh.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Cosh>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Cosh"; }
         };
     }

src/ngraph/ops/divide.hpp

@@ -52,6 +52,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Divide>(new_args.at(0), new_args.at(1));
+            }
+
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,
                                            const std::shared_ptr<Node>& delta) override;
 

src/ngraph/ops/dot.hpp

@@ -114,6 +114,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Dot>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Dot"; }
             virtual void propagate_types() override;
 

src/ngraph/ops/equal.hpp

@@ -51,6 +51,15 @@ namespace ngraph
                 : BinaryElementwiseComparison(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Equal>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Equal"; }
         };
     }

src/ngraph/ops/exp.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Exp>(new_args.at(0));
+            }
+
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,
                                            const std::shared_ptr<Node>& delta) override;
 

src/ngraph/ops/floor.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Floor>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Floor"; }
         };
     }

src/ngraph/ops/function_call.hpp

@@ -60,6 +60,12 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                return std::make_shared<FunctionCall>(m_function, new_args);
+            }
+
             virtual std::string description() const override { return "FunctionCall"; }
             virtual void propagate_types() override;
 

src/ngraph/ops/get_tuple_element.hpp

@@ -60,6 +60,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<GetTupleElement>(new_args.at(0), m_n);
+            }
+
             virtual void propagate_types() override;
             virtual std::string description() const override { return "GetTupleElement"; }
             /// \return The index of the tuple element to get.

src/ngraph/ops/greater.hpp

@@ -51,6 +51,15 @@ namespace ngraph
                 : BinaryElementwiseComparison(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Greater>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Greater"; }
         };
     }

src/ngraph/ops/greater_eq.hpp

@@ -51,6 +51,15 @@ namespace ngraph
                 : BinaryElementwiseComparison(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<GreaterEq>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "GreaterEq"; }
         };
     }

src/ngraph/ops/less.hpp

@@ -51,6 +51,15 @@ namespace ngraph
                 : BinaryElementwiseComparison(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Less>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Less"; }
         };
     }

src/ngraph/ops/less_eq.hpp

@@ -51,6 +51,15 @@ namespace ngraph
                 : BinaryElementwiseComparison(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<LessEq>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "LessEq"; }
         };
     }

src/ngraph/ops/log.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Log>(new_args.at(0));
+            }
+
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,
                                            const std::shared_ptr<Node>& delta) override;
 

src/ngraph/ops/maximum.hpp

@@ -51,6 +51,15 @@ namespace ngraph
                 : BinaryElementwiseArithmetic(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Maximum>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Maximum"; }
         protected:
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,

src/ngraph/ops/minimum.hpp

@@ -51,6 +51,15 @@ namespace ngraph
                 : BinaryElementwiseArithmetic(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Minimum>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Minimum"; }
         protected:
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,

src/ngraph/ops/multiply.hpp

@@ -52,6 +52,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Multiply>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Multiply"; }
         protected:
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,

src/ngraph/ops/negative.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Negative>(new_args.at(0));
+            }
+
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,
                                            const std::shared_ptr<Node>& delta) override;
 

src/ngraph/ops/not_equal.hpp

@@ -51,6 +51,15 @@ namespace ngraph
                 : BinaryElementwiseComparison(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<NotEqual>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "NotEqual"; }
         };
     }

src/ngraph/ops/parameter.hpp

@@ -62,6 +62,14 @@ namespace ngraph
             /// \param shape The shape of the parameter.
             Parameter(const ngraph::element::Type& element_type, const Shape& shape);
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 0)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Parameter>(get_value_type());
+            }
+
             std::string description() const override { return "Parameter"; }
             virtual void propagate_types() override;
         };

src/ngraph/ops/power.hpp

@@ -51,6 +51,15 @@ namespace ngraph
                 : BinaryElementwiseArithmetic(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Power>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Power"; }
         };
     }

src/ngraph/ops/reduce.hpp

@@ -106,6 +106,15 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Reduce>(
+                    new_args.at(0), new_args.at(1), m_reduction_function, m_reduction_axes);
+            }
+
             virtual std::string description() const override { return "Reduce"; }
             virtual void propagate_types() override;
 

src/ngraph/ops/remainder.hpp

@@ -53,6 +53,15 @@ namespace ngraph
                 : BinaryElementwiseArithmetic(arg0, arg1)
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Remainder>(new_args.at(0), new_args.at(1));
+            }
+
             virtual std::string description() const override { return "Remainder"; }
         };
     }

src/ngraph/ops/reshape.hpp

@@ -78,6 +78,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Reshape>(new_args.at(0), m_input_order, m_output_shape);
+            }
+
             virtual std::string description() const override { return "Reshape"; }
             virtual void propagate_types() override;
 

src/ngraph/ops/select.hpp

@@ -55,6 +55,15 @@ namespace ngraph
                 : Builtin(Nodes{arg0, arg1, arg2})
             {
             }
+
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 3)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Select>(new_args.at(0), new_args.at(1), new_args.at(2));
+            }
+
             virtual std::string description() const override { return "Select"; }
             virtual void propagate_types() override;
         };

src/ngraph/ops/sign.hpp

@@ -52,6 +52,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Sign>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Sign"; }
         };
     }

src/ngraph/ops/sin.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Sin>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Sin"; }
         };
     }

src/ngraph/ops/sinh.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Sinh>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Sinh"; }
         };
     }

src/ngraph/ops/slice.hpp

@@ -88,6 +88,15 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Slice>(
+                    new_args.at(0), m_lower_bounds, m_upper_bounds, m_step);
+            }
+
             virtual std::string description() const override { return "Slice"; }
             virtual void propagate_types() override;
 

src/ngraph/ops/subtract.hpp

@@ -52,6 +52,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 2)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Subtract>(new_args.at(0), new_args.at(1));
+            }
+
             virtual void generate_adjoints(autodiff::Adjoints& adjoints,
                                            const std::shared_ptr<Node>& delta) override;
 

src/ngraph/ops/sum.hpp

@@ -93,6 +93,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Sum>(new_args.at(0), m_reduction_axes);
+            }
+
             virtual std::string description() const override { return "Sum"; }
             virtual void propagate_types() override;
 

src/ngraph/ops/tan.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Tan>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Tan"; }
         };
     }

src/ngraph/ops/tanh.hpp

@@ -50,6 +50,14 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                if (new_args.size() != 1)
+                    throw ngraph_error("Incorrect number of new arguments");
+                return std::make_shared<Tanh>(new_args.at(0));
+            }
+
             virtual std::string description() const override { return "Tanh"; }
         };
     }

src/ngraph/ops/tuple.hpp

@@ -50,6 +50,12 @@ namespace ngraph
             {
             }
 
+            virtual std::shared_ptr<Node> copy_with_new_args(
+                const std::vector<std::shared_ptr<Node>>& new_args) const override
+            {
+                return std::make_shared<Tuple>(new_args);
+            }
+
             virtual std::string description() const override { return "Tuple"; }
             virtual void propagate_types() override;
         };

src/ngraph/runtime/ndarray.hpp

@@ -177,6 +177,8 @@ namespace ngraph
             const_iterator end() const { return m_elements.end(); }
             vtype get_vector() { return m_elements; }
             const vtype get_vector() const { return m_elements; }
+            operator const vtype() const { return m_elements; }
+            operator vtype() { return m_elements; }
             bool operator==(const NDArrayBase<T>& other) const
             {
                 return m_shape == other.m_shape && m_elements == other.m_elements;

src/ngraph/types/type.cpp

@@ -70,6 +70,11 @@ const Shape& TupleType::get_shape() const
     throw ngraph_error("get_shape() called on Tuple");
 }
 
+const element::Type& TupleType::get_element_type() const
+{
+    throw ngraph_error("get_element_type() called on Tuple");
+}
+
 std::ostream& ngraph::operator<<(std::ostream& out, const ValueType& obj)
 {
     out << "ValueType()";

src/ngraph/types/type.hpp

@@ -43,6 +43,7 @@ namespace ngraph
         virtual void collect_tensor_views(
             std::vector<std::shared_ptr<const TensorViewType>>& views) const = 0;
         virtual const Shape& get_shape() const = 0;
+        virtual const element::Type& get_element_type() const = 0;
         friend std::ostream& operator<<(std::ostream&, const ValueType&);
     };
 
@@ -59,7 +60,7 @@ namespace ngraph
         {
         }
 
-        const element::Type& get_element_type() const { return m_element_type; }
+        virtual const element::Type& get_element_type() const override { return m_element_type; }
         virtual const Shape& get_shape() const override { return m_shape; }
         virtual bool operator==(const ValueType& that) const override;
         virtual void collect_tensor_views(
@@ -93,6 +94,8 @@ namespace ngraph
             return m_element_types;
         }
 
+        virtual const element::Type& get_element_type() const override;
+
         virtual bool operator==(const ValueType& that) const override;
         virtual void collect_tensor_views(
             std::vector<std::shared_ptr<const TensorViewType>>& views) const override;

test/CMakeLists.txt

@@ -23,6 +23,7 @@ include_directories(
 
 set (SRC
     autodiff.cpp
+    copy.cpp
     build_graph.cpp
     eigen.cpp
     input_output_assign.cpp