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## Struct template derivation_value_traits

boost::intrusive::derivation_value_traits

## Synopsis

    // In header: <boost/intrusive/derivation_value_traits.hpp>

    template<typename T, typename NodeTraits, link_mode_type LinkMode = safe_link>
    struct derivation_value_traits {
      // types
      typedef NodeTraits                                                   node_traits;
      typedef T                                                            value_type;
      typedef node_traits::node                                            node;
      typedef node_traits::node_ptr                                        node_ptr;
      typedef node_traits::const_node_ptr                                  const_node_ptr;
      typedef boost::pointer_to_other< node_ptr, T >::type                 pointer;
      typedef boost::pointer_to_other< node_ptr, const T >::type           const_pointer;
      typedef boost::intrusive::pointer_traits< pointer >::reference       reference;
      typedef boost::intrusive::pointer_traits< const_pointer >::reference const_reference;

      // public static functions
      static node_ptr to_node_ptr(reference);
      static const_node_ptr to_node_ptr(const_reference);
      static pointer to_value_ptr(const node_ptr &);
      static const_pointer to_value_ptr(const const_node_ptr &);

      // public data members
      static const link_mode_type link_mode;
    };

## Description

This value traits template is used to create value traits from user defined node traits where value_traits::value_type will derive from node_traits::node

### `derivation_value_traits` public static functions

1.     static node_ptr to_node_ptr(reference value);

2.     static const_node_ptr to_node_ptr(const_reference value);

3.     static pointer to_value_ptr(const node_ptr & n);

4.     static const_pointer to_value_ptr(const const_node_ptr & n);