node.hpp

//*****************************************************************************
// Copyright 2017-2021 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 <atomic>
#include <cstring>
#include <deque>
#include <iostream>
#include <map>
#include <memory>
#include <set>
#include <string>
#include <tuple>
#include <typeindex>
#include <unordered_map>
#include <unordered_set>
#include <vector>
 
#include "ngraph/attribute_visitor.hpp"
#include "ngraph/check.hpp"
#include "ngraph/coordinate.hpp"
#include "ngraph/coordinate_diff.hpp"
#include "ngraph/deprecated.hpp"
#include "ngraph/descriptor/input.hpp"
#include "ngraph/descriptor/output.hpp"
#include "ngraph/descriptor/tensor.hpp"
#include "ngraph/node_input.hpp"
#include "ngraph/node_output.hpp"
#include "ngraph/op/util/attr_types.hpp"
#include "ngraph/op/util/op_annotations.hpp"
#include "ngraph/output_vector.hpp"
#include "ngraph/strides.hpp"
#include "ngraph/type.hpp"
 
namespace ngraph
{
    template <typename NodeType>
    class Input;
 
    template <typename NodeType>
    class Output;
 
    class AttributeVisitor;
    class Variant;
    class Node;
 
    class Function;
 
    namespace runtime
    {
        class HostTensor;
    }
    using HostTensor = runtime::HostTensor;
    using HostTensorPtr = std::shared_ptr<HostTensor>;
    using HostTensorVector = std::vector<HostTensorPtr>;
 
    namespace op
    {
        struct AutoBroadcastSpec;
 
        namespace v0
        {
            class Result;
        }
    } // namespace op
 
    namespace pattern
    {
        class Matcher;
    }
 
    using ResultVector = std::vector<std::shared_ptr<op::v0::Result>>;
 
    NGRAPH_API
    std::string node_validation_failure_loc_string(const Node* node);
 
    const std::shared_ptr<Node>& check_single_output_arg(const std::shared_ptr<Node>& node,
                                                         size_t i);
    NGRAPH_API
    const NodeVector& check_single_output_args(const NodeVector& args);
 
    const std::shared_ptr<Node>& check_single_output_arg(const std::shared_ptr<Node>& node,
                                                         size_t i);
 
    NGRAPH_API
    OutputVector as_output_vector(const NodeVector& args);
    NGRAPH_API
    NodeVector as_node_vector(const OutputVector& values);
    /// Returns a ResultVector referencing values.
    NGRAPH_API
    ResultVector as_result_vector(const OutputVector& values);
 
    /// Alias useful for cloning
    using NodeMap = std::unordered_map<ngraph::Node*, std::shared_ptr<ngraph::Node>>;
 
/// \brief Used in evaluator switch statement so that the case type and evaluate call
/// are guaranteed to have the types match.
///
/// Use this in an evaluate_*() function like this
///    switch (arg0->get_element_type())
///    {
///        TYPE_CASE(i8)(arg0, arg1, out, broadcast_spec); break;
///        TYPE_CASE(i16)(arg0, arg1, out, broadcast_spec); break;
///
/// Each TYPE_CASE statement expands like this:
///   case element::Type_t::a: rc = evaluate<element::Type_t::a>(arg0, arg1, out, broadcast_spec)
///
/// \note Don't forget to put a break after each statement or it will fall through and generate
/// a runtime error.
 
#define TYPE_CASE(a)                                                                               \
    case element::Type_t::a: rc = evaluate<element::Type_t::a>
 
    /// Nodes are the backbone of the graph of Value dataflow. Every node has
    /// zero or more nodes as arguments and one value, which is either a tensor
    /// or a (possibly empty) tuple of values.
    class NGRAPH_API Node : public std::enable_shared_from_this<Node>
    {
        // For access to m_outputs.
        friend class descriptor::Input;
 
        // For access to m_inputs and m_outputs.
        template <typename NodeType>
        friend class Input;
 
        // For access to m_outputs.
        template <typename NodeType>
        friend class Output;
 
    public:
        /// \brief Verifies that attributes and inputs are consistent and computes output shapes
        /// and element types. Must be implemented by concrete child classes so that it
        /// can be run any number of times.
        ///
        /// Throws if the node is invalid.
        virtual void validate_and_infer_types();
 
        // Called in constructors during transition
        void constructor_validate_and_infer_types();
 
        using type_info_t = DiscreteTypeInfo;
 
    protected:
        /// \brief Construct an unitialized Node
        Node() = default;
        /// \brief Copying a node
        Node(const Node&);
        /// \brief Assignment operator
        Node& operator=(const Node&);
 
        /// \brief Construct an unitialized Node
        /// \param output_size Number of outputs for this node
        Node(size_t output_size);
 
        /// \brief Constructor for Node subclasses that have metaclasses.
        /// \param arguments Output i will connect to input i
        /// \param output_size Number of outputs for this node
        Node(const OutputVector& arguments, size_t output_size = 1);
        /// \brief Moves nodes that would be deleted from inputs to nodes to avoid stack overflows
        /// on deep networks.
        void safe_delete(NodeVector& nodes, bool recurse);
 
        /// \brief Marks an input as being relevant or irrelevant to the output shapes of this
        ///        node.
        /// \param i The index of the input to mark as relevant or irrelevant.
        /// \param relevant true if the input is relevant to output shapes, false otherwise.
        ///
        /// This is used by the shape specialization pass to know which nodes must be statically
        /// evaluated in order to complete shape specialization. (For example, the shape input of
        /// DynReshape must be evaluated statically in order for the output shape to be
        /// determined.) By default, all inputs are marked as shape-irrelevant. Overrides of
        /// validate_and_infer_types should call this function to mark shape-relevant inputs.
        void set_input_is_relevant_to_shape(size_t i, bool relevant = true);
 
        /// \brief Marks an input as being relevant or irrelevant to the output values of this
        ///        node.
        /// \param i The index of the input to mark as relevant or irrelevant.
        /// \param relevant true if the input is relevant to output values, false otherwise.
        ///
        /// This is used by the shape specialization pass to cut short evaluation in cases where
        /// an input value does not actually have any effect on the output value of the node. (As
        /// of this writing, the only example of this is ShapeOf.) By default, all inputs are
        /// marked as value-relevant. Overrides of validate_and_infer_types should call this
        /// function to mark value-irrelevant inputs.
        void set_input_is_relevant_to_value(size_t i, bool relevant = true);
 
    public:
        virtual ~Node();
 
        virtual bool visit_attributes(AttributeVisitor&) { return false; }
        /// \returns the autobroadcasr spec
        virtual const op::AutoBroadcastSpec& get_autob() const;
        /// \brief Evaluates the op on input_values putting results in output_values
        /// \returns true if successful
        virtual bool evaluate(const HostTensorVector& output_values,
                              const HostTensorVector& input_values) const;
        virtual bool evaluate_lower(const HostTensorVector& output_values) const;
        virtual bool evaluate_upper(const HostTensorVector& output_values) const;
 
        virtual bool constant_fold(OutputVector& output_values, const OutputVector& inputs_values);
        /// \brief Decomposes the FusedOp into a sub-graph consisting of core ngraph ops
        ///
        /// \return A vector of nodes comprising the sub-graph. The order of output
        ///         tensors must match the match output tensors of the FusedOp
        virtual OutputVector decompose_op() const { return OutputVector(); }
        /// Returns the NodeTypeInfo for the node's class.
        /// During transition to type_info, returns a dummy type_info for Node if the class
        /// has not been updated yet.
        virtual const type_info_t& get_type_info() const = 0;
        const char* get_type_name() const { return get_type_info().name; }
        /// Sets/replaces the arguments with new arguments.
        void set_arguments(const NodeVector& arguments);
        /// Sets/replaces the arguments with new arguments.
        void set_arguments(const OutputVector& arguments);
        /// Sets/replaces the arguments with new arguments.
        void set_argument(size_t position, const Output<Node>& argument);
 
        void set_output_type(size_t i,
                             const element::Type& element_type,
                             const PartialShape& pshape);
 
        /// Sets the number of outputs
        void set_output_size(size_t output_size);
 
        void invalidate_values();
        virtual void revalidate_and_infer_types()
        {
            invalidate_values();
            validate_and_infer_types();
        }
        /// \brief Get the string name for the type of the node, such as `Add` or `Multiply`.
        ///        The class name, must not contain spaces as it is used for codegen.
        /// \returns A const reference to the node's type name
        virtual std::string description() const;
        /// \brief Get the unique name of the node.
        /// \returns A const reference to the node's unique name.
        const std::string& get_name() const;
 
        /// \brief Sets a friendly name for a node. This does not overwrite the unique name
        ///        of the node and is retrieved via get_friendly_name(). Used mainly for debugging.
        ///        The friendly name may be set exactly once.
        /// \param name is the friendly name to set
        void set_friendly_name(const std::string& name);
 
        /// \brief Gets the friendly name for a node. If no friendly name has been set via
        ///        set_friendly_name then the node's unique name is returned.
        /// \returns A const reference to the node's friendly name.
        const std::string& get_friendly_name() const;
 
        virtual bool is_dynamic() const;
        size_t get_instance_id() const { return m_instance_id; }
        /// \brief Writes a description of a node to a stream
        /// \param os The stream; should be returned
        /// \param depth How many levels of inputs to describe
        /// \returns The stream os
        virtual std::ostream& write_description(std::ostream& os, uint32_t depth = 0) const;
 
        /// Get control dependencies registered on the node
        const std::vector<std::shared_ptr<Node>>& get_control_dependencies() const;
 
        /// Get nodes dependent on this node
        const std::vector<Node*>& get_control_dependents() const;
 
        /// This node cannot execute until node executes
        void add_control_dependency(std::shared_ptr<Node> node);
 
        /// Remove the dependency of this node on node
        void remove_control_dependency(std::shared_ptr<Node> node);
 
        /// Remove all dependencies from this node
        void clear_control_dependencies();
 
        /// Remove this node as a dependency from all dependent nodes
        void clear_control_dependents();
 
        /// This node absorbs the control dependencies of source_node
        void add_node_control_dependencies(std::shared_ptr<Node> source_node);
 
        /// This node becomes a dependent of every node dependent on source_node
        void add_node_control_dependents(std::shared_ptr<Node> source_node);
 
        /// This node's control dependencies are replaced by replacement
        void transfer_control_dependents(std::shared_ptr<Node> replacement);
 
        /// Returns the number of outputs from the node.
        size_t get_output_size() const;
 
        /// Returns the element type for output i
        const element::Type& get_output_element_type(size_t i) const;
 
        /// Checks that there is exactly one output and returns its element type
        // TODO: deprecate in favor of node->get_output_element_type(0) with a suitable check in
        // the calling code, or updates to the calling code if it is making an invalid assumption
        // of only one output.
        const element::Type& get_element_type() const;
 
        /// Returns the shape for output i
        const Shape& get_output_shape(size_t i) const;
 
        /// Returns the partial shape for output i
        const PartialShape& get_output_partial_shape(size_t i) const;
 
        /// Return the output to use when converting to an Output<Node> with no index specified.
        /// Throws when not supported.
        Output<const Node> get_default_output() const;
        Output<Node> get_default_output();
 
        /// Returns the output of the default output, or throws if there is none
        virtual size_t get_default_output_index() const;
        /// Throws no default
        size_t no_default_index() const;
 
        /// Checks that there is exactly one output and returns its shape
        // TODO: deprecate in favor of node->get_output_shape(0) with a suitable check in the
        // calling code, or updates to the calling code if it is making an invalid assumption of
        // only one output.
        const Shape& get_shape() const;
 
        /// Returns the tensor for output or input i
        descriptor::Tensor& get_output_tensor(size_t i) const;
        descriptor::Tensor& get_input_tensor(size_t i) const;
 
        /// Returns the tensor name for output i
        NGRAPH_DEPRECATED(
            "The tensor name was deprecated. Use get_output_tensor(i).get_names() instead.")
        const std::string& get_output_tensor_name(size_t i) const;
 
        std::set<Input<Node>> get_output_target_inputs(size_t i) const;
 
        /// Returns the number of inputs for the op
        size_t get_input_size() const;
 
        /// Returns the element type of input i
        // TODO: deprecate in favor of node->get_input_element_type(i)
        const element::Type& get_input_element_type(size_t i) const;
 
        /// Returns the shape of input i
        // TODO: deprecate in favor of node->get_input_shape(i)
        const Shape& get_input_shape(size_t i) const;
 
        /// Returns the partial shape of input i
        // TODO: deprecate in favor of node->get_input_partial_shape(i)
        const PartialShape& get_input_partial_shape(size_t i) const;
 
        /// Returns the tensor name for input i
        NGRAPH_DEPRECATED(
            "The tensor name was deprecated. Use get_input_tensor(i).get_names() instead.")
        const std::string& get_input_tensor_name(size_t i) const;
 
        std::unordered_set<descriptor::Tensor*> liveness_new_list;
        std::unordered_set<descriptor::Tensor*> liveness_free_list;
 
        Node* get_input_node_ptr(size_t index) const;
        std::shared_ptr<Node> get_input_node_shared_ptr(size_t index) const;
        Output<Node> get_input_source_output(size_t i) const;
 
    public:
        virtual std::shared_ptr<Node> clone_with_new_inputs(const OutputVector& inputs) const = 0;
 
        std::shared_ptr<Node> copy_with_new_inputs(const OutputVector& new_args) const;
 
        std::shared_ptr<Node> copy_with_new_inputs(
            const OutputVector& inputs,
            const std::vector<std::shared_ptr<Node>>& control_dependencies) const;
 
        /// True if this and node have one output with same element type and shape
        bool has_same_type(std::shared_ptr<const Node> node) const;
 
        using RTMap = std::map<std::string, std::shared_ptr<Variant>>;
 
        RTMap& get_rt_info() { return m_rt_info; }
        const RTMap& get_rt_info() const { return m_rt_info; }
        const std::unordered_set<std::string>& get_provenance_tags() const;
        void add_provenance_tag(const std::string& tag);
        template <typename T>
        void add_provenance_tags(T tag_set)
        {
            for (auto tag : tag_set)
            {
                add_provenance_tag(tag);
            }
        }
        /// \brief Adds tag_set to this node and all intermediate nodes above base
        void add_provenance_tags_above(const OutputVector& base,
                                       const std::unordered_set<std::string>& tag_set);
        void remove_provenance_tag(const std::string& tag);
        /// \brief Add node to additional nodes that receive tags
        void add_provenance_group_member(const std::shared_ptr<Node>& node);
        /// \brief Remove node to additional nodes that receive tags
        void remove_provenance_group_member(const std::shared_ptr<Node>& node);
        /// \brief Replace current_node with replacement_node and transfer tags
        void replace_provenance_group_member(const std::shared_ptr<Node>& current_node,
                                             const std::shared_ptr<Node>& replacement_node);
        /// \return Provenance group nodes
        const std::set<std::shared_ptr<Node>>& get_provenance_group_members() const;
 
        /// \brief Add all nodes between this node and nodes in base as additional nodes to receive
        /// provenance tags.
        std::shared_ptr<Node> add_provenance_group_members_above(const OutputVector& base);
 
        // to be used when nodes are replaced
        void merge_provenance_tags_from(const std::shared_ptr<const Node>& source);
 
        /// Transfer provenance tags to replacement
        void transfer_provenance_tags(const std::shared_ptr<Node>& replacement);
 
        /// Get all the nodes that uses the current node
        NodeVector get_users(bool check_is_used = false) const;
 
        /// \return Version of this node
        virtual size_t get_version() const { return get_type_info().version; }
        virtual std::shared_ptr<Node> get_default_value() const { return nullptr; }
        /// Use instance ids for comparison instead of memory addresses to improve determinism
        bool operator<(const Node& other) const { return m_instance_id < other.m_instance_id; }
        /// \return A vector containing a handle for each of this node's inputs, in order.
        // TODO: Rename to get_inputs()?
        std::vector<Input<Node>> inputs();
 
        /// \return A vector containing a handle for each of this node's inputs, in order.
        std::vector<Input<const Node>> inputs() const;
 
        /// \return A vector containing the values for each input
        std::vector<Output<Node>> input_values() const;
 
        /// \return A vector containing a handle for each of this node's outputs, in order.
        // TODO: Rename to get_outputs()?
        std::vector<Output<Node>> outputs();
 
        /// \return A vector containing a handle for each of this node's outputs, in order.
        std::vector<Output<const Node>> outputs() const;
 
        /// \return A handle to the `input_index`th input of this node.
        /// \throw std::out_of_range if the node does not have at least `input_index+1` inputs.
        Input<Node> input(size_t input_index);
 
        /// \return A handle to the `input_index`th input of this node.
        /// \throw std::out_of_range if the node does not have at least `input_index+1` inputs.
        Input<const Node> input(size_t input_index) const;
 
        Output<Node> input_value(size_t input_index) const;
 
        /// \return A handle to the `output_index`th output of this node.
        /// \throw std::out_of_range if the node does not have at least `output_index+1` outputs.
        Output<Node> output(size_t output_index);
 
        /// \return A handle to the `output_index`th output of this node.
        /// \throw std::out_of_range if the node does not have at least `output_index+1` outputs.
        Output<const Node> output(size_t output_index) const;
 
        void set_op_annotations(std::shared_ptr<ngraph::op::util::OpAnnotations> op_annotations)
        {
            m_op_annotations = op_annotations;
        }
        std::shared_ptr<ngraph::op::util::OpAnnotations> get_op_annotations() const
        {
            return m_op_annotations;
        }
 
        virtual bool match_value(pattern::Matcher* matcher,
                                 const Output<Node>& pattern_value,
                                 const Output<Node>& graph_value);
 
        virtual bool match_node(pattern::Matcher* matcher, const Output<Node>& graph_value);
 
    private:
        descriptor::Input& get_input_descriptor(size_t position);
        descriptor::Output& get_output_descriptor(size_t position);
 
        std::vector<Node*> m_control_dependents;
        std::vector<std::shared_ptr<Node>> m_control_dependencies;
        std::string m_node_type;
        size_t m_instance_id{m_next_instance_id.fetch_add(1)};
        std::string m_friendly_name;
        std::string m_unique_name;
        static std::atomic<size_t> m_next_instance_id;
        std::unordered_set<std::string> m_provenance_tags;
        std::set<std::shared_ptr<Node>> m_provenance_group;
        std::deque<descriptor::Input> m_inputs;
        std::deque<descriptor::Output> m_outputs;
        std::shared_ptr<ngraph::op::util::OpAnnotations> m_op_annotations;
        std::map<std::string, std::shared_ptr<Variant>> m_rt_info;
    };
 
    using NodeTypeInfo = Node::type_info_t;
 
    NGRAPH_API std::ostream& operator<<(std::ostream&, const Node&);
    NGRAPH_API std::ostream& operator<<(std::ostream&, const Node*);
 
#define _NGRAPH_RTTI_EXPAND(X) X
 
/// Helper macro that puts necessary declarations of RTTI block inside a class definition.
/// Should be used in the scope of class that requires type identification besides one provided by
/// C++ RTTI.
/// Recommended to be used for all classes that are inherited from class ngraph::Node to enable
/// pattern
/// matching for them. Accepts necessary type identification details like type of the operation,
/// version and optional parent class.
///
/// Applying this macro within a class definition provides declaration of type_info static
/// constant for backward compatibility with old RTTI definition for Node,
/// static function get_type_info_static which returns a reference to an object that is equal to
/// type_info but not necessary to the same object, and get_type_info virtual function that
/// overrides Node::get_type_info and returns a reference to the same object that
/// get_type_info_static gives.
///
/// Use this macro as a public part of the class definition:
///
///     class MyOp : public Node
///     {
///         public:
///             // Don't use Node as a parent for type_info, it doesn't have any value and
///             prohibited
///             NGRAPH_RTTI_DECLARATION;
///
///             ...
///     };
///
///     class MyInheritedOp : public MyOp
///     {
///         public:
///             NGRAPH_RTTI_DECLARATION;
///
///             ...
///     };
///
/// To complete type identification for a class, use NGRAPH_RTTI_DEFINITION.
///
#define NGRAPH_RTTI_DECLARATION                                                                    \
    static const ::ngraph::Node::type_info_t type_info;                                            \
    const ::ngraph::Node::type_info_t& get_type_info() const override;                             \
    static const ::ngraph::Node::type_info_t& get_type_info_static()
 
#define _NGRAPH_RTTI_DEFINITION_COMMON(CLASS)                                                      \
    const ::ngraph::Node::type_info_t& CLASS::get_type_info() const                                \
    {                                                                                              \
        return get_type_info_static();                                                             \
    }                                                                                              \
    const ::ngraph::Node::type_info_t CLASS::type_info = CLASS::get_type_info_static()
#define _NGRAPH_RTTI_DEFINITION_WITH_PARENT(CLASS, TYPE_NAME, _VERSION_INDEX, PARENT_CLASS)        \
    const ::ngraph::Node::type_info_t& CLASS::get_type_info_static()                               \
    {                                                                                              \
        static const ::ngraph::Node::type_info_t type_info_static{                                 \
            TYPE_NAME, _VERSION_INDEX, &PARENT_CLASS::get_type_info_static()};                     \
        return type_info_static;                                                                   \
    }                                                                                              \
    _NGRAPH_RTTI_DEFINITION_COMMON(CLASS)
 
#define _NGRAPH_RTTI_DEFINITION_NO_PARENT(CLASS, TYPE_NAME, _VERSION_INDEX)                        \
    const ::ngraph::Node::type_info_t& CLASS::get_type_info_static()                               \
    {                                                                                              \
        static const ::ngraph::Node::type_info_t type_info_static{TYPE_NAME, _VERSION_INDEX};      \
        return type_info_static;                                                                   \
    }                                                                                              \
    _NGRAPH_RTTI_DEFINITION_COMMON(CLASS)
 
#define _NGRAPH_RTTI_DEFINITION_SELECTOR(_1, _2, _3, _4, NAME, ...) NAME
 
/// Complementary to NGRAPH_RTTI_DECLARATION, this helper macro _defines_ items _declared_ by
/// NGRAPH_RTTI_DECLARATION.
/// Should be used outside the class definition scope in place where ODR is ensured.
///
/// \param CLASS is a C++ name of the class where corresponding NGRAPH_RTTI_DECLARATION was applied.
/// \param TYPE_NAME a string literal of type const char* that names your class in type
/// identification namespace;
///        It is your choice how to name it, but it should be unique among all
///        NGRAPH_RTTI_DECLARATION-enabled classes that can be
///        used in conjunction with each other in one transformation flow.
/// \param _VERSION_INDEX is an unsigned integer index to distinguish different versions of
///        operations that shares the same TYPE_NAME
/// \param PARENT_CLASS is an optional direct or indirect parent class for this class; define
///        it only in case if there is a need to capture any operation from some group of operations
///        that all derived from some common base class. Don't use Node as a parent, it is a base
///        class
///        for all operations and doesn't provide ability to define some perfect subset of
///        operations. PARENT_CLASS should define RTTI with NGRAPH_RTTI_{DECLARATION/DEFINITION}
///        macros.
///
/// Examples (see corresponding declarations in NGRAPH_RTTI_DECLARATION description):
///
///     NGRAPH_RTTI_DEFINITION(MyOp,"MyOp", 1);
///     NGRAPH_RTTI_DEFINITION(MyInheritedOp, "MyInheritedOp", 1, MyOp)
///
/// For convenience, TYPE_NAME and CLASS name are recommended to be the same.
///
#define NGRAPH_RTTI_DEFINITION(...)                                                                \
    _NGRAPH_RTTI_EXPAND(_NGRAPH_RTTI_DEFINITION_SELECTOR(                                          \
        __VA_ARGS__, _NGRAPH_RTTI_DEFINITION_WITH_PARENT, _NGRAPH_RTTI_DEFINITION_NO_PARENT)(      \
        __VA_ARGS__))
 
    // Like an Output but with a Node* instead of a shared_ptr<Node>
    struct RawNodeOutput
    {
        RawNodeOutput(const Output<Node>& value)
            : node(value.get_node())
            , index(value.get_index())
        {
        }
        RawNodeOutput(Node* node, size_t index)
            : node(node)
            , index(index)
        {
        }
        RawNodeOutput(const RawNodeOutput&) = default;
        RawNodeOutput() = default;
        RawNodeOutput& operator=(const RawNodeOutput&) = default;
 
        Node* node;
        size_t index{0};
 
        operator Output<Node>() { return Output<Node>(node->shared_from_this(), index); }
        bool operator==(const RawNodeOutput& other) const
        {
            return node == other.node && index == other.index;
        }
        bool operator!=(const RawNodeOutput& other) const { return !(*this == other); }
        bool operator<(const RawNodeOutput& other) const
        {
            return node < other.node || (node == other.node && index < other.index);
        }
        bool operator>(const RawNodeOutput& other) const
        {
            return node > other.node || (node == other.node && index > other.index);
        }
        bool operator<=(const RawNodeOutput& other) const { return !(*this > other); }
        bool operator>=(const RawNodeOutput& other) const { return !(*this < other); }
    };
 
    /// \brief Visits a reference to a node that has been registered with the visitor.
    template <>
    class NGRAPH_API AttributeAdapter<std::shared_ptr<Node>> : public VisitorAdapter
    {
    public:
        AttributeAdapter(std::shared_ptr<Node>& value);
 
        bool visit_attributes(AttributeVisitor& visitor) override;
        static constexpr DiscreteTypeInfo type_info{"AttributeAdapter<std::shared_ptr<Node>>", 0};
        const DiscreteTypeInfo& get_type_info() const override { return type_info; }
    protected:
        std::shared_ptr<Node>& m_ref;
    };
 
    template <>
    class NGRAPH_API AttributeAdapter<NodeVector> : public VisitorAdapter
    {
    public:
        AttributeAdapter(NodeVector& ref);
 
        bool visit_attributes(AttributeVisitor& visitor) override;
 
        static constexpr DiscreteTypeInfo type_info{"AttributeAdapter<NodeVector>", 0};
        const DiscreteTypeInfo& get_type_info() const override { return type_info; }
    protected:
        NodeVector& m_ref;
    };
 
    using RawNodeOutputMap = std::map<RawNodeOutput, Output<Node>>;
 
    class NGRAPH_API NodeValidationFailure : public CheckFailure
    {
    public:
        NodeValidationFailure(const CheckLocInfo& check_loc_info,
                              const Node* node,
                              const std::string& explanation)
            : CheckFailure(check_loc_info, node_validation_failure_loc_string(node), explanation)
        {
        }
    };
}
#define NODE_VALIDATION_CHECK(node, ...)                                                           \
    NGRAPH_CHECK_HELPER(::ngraph::NodeValidationFailure, (node), __VA_ARGS__)
 
namespace ngraph
{
    template <typename T>
    void check_new_args_count(const Node* node, T new_args)
    {
        NODE_VALIDATION_CHECK(node,
                              new_args.size() == node->input_values().size(),
                              "clone_with_new_inputs() expected ",
                              node->input_values().size(),
                              " argument",
                              (node->input_values().size() == 1 ? "" : "s"),
                              " but got ",
                              new_args.size());
    }
 
} // namespace ngraph