text: //////////////////////////////////////////////////////////////////////////////
  //
  // (C) Copyright Ion Gaztanaga 2005. 
  // Distributed under the Boost Software License, Version 1.0. 
  // (See accompanying file LICENSE_1_0.txt or copy at 
  //  http://www.boost.org/LICENSE_1_0.txt)
  //
  //////////////////////////////////////////////////////////////////////////////
  
  #ifndef BOOST_POINTER_CAST_HPP
  #define BOOST_POINTER_CAST_HPP
  
  #include <boost/config.hpp>
  #include <boost/smart_ptr/detail/sp_noexcept.hpp>
  
  namespace boost { 
  
  //static_pointer_cast overload for raw pointers
  template<class T, class U>
  inline T* static_pointer_cast(U *ptr) BOOST_SP_NOEXCEPT
  {  
     return static_cast<T*>(ptr);
  }
  
  //dynamic_pointer_cast overload for raw pointers
  template<class T, class U>
  inline T* dynamic_pointer_cast(U *ptr) BOOST_SP_NOEXCEPT
  {  
     return dynamic_cast<T*>(ptr);
  }
  
  //const_pointer_cast overload for raw pointers
  template<class T, class U>
  inline T* const_pointer_cast(U *ptr) BOOST_SP_NOEXCEPT
  {  
     return const_cast<T*>(ptr);
  }
  
  //reinterpret_pointer_cast overload for raw pointers
  template<class T, class U>
  inline T* reinterpret_pointer_cast(U *ptr) BOOST_SP_NOEXCEPT
  {  
     return reinterpret_cast<T*>(ptr);
  }
  
  } // namespace boost
  
  #if !defined( BOOST_NO_CXX11_SMART_PTR )
  
  #include <boost/type_traits/has_virtual_destructor.hpp>
  #include <boost/static_assert.hpp>
  #include <memory>
  
  namespace boost {
  
  //static_pointer_cast overload for std::shared_ptr
  using std::static_pointer_cast;
  
  //dynamic_pointer_cast overload for std::shared_ptr
  using std::dynamic_pointer_cast;
  
  //const_pointer_cast overload for std::shared_ptr
  using std::const_pointer_cast;
  
  //reinterpret_pointer_cast overload for std::shared_ptr
  template<class T, class U> std::shared_ptr<T> reinterpret_pointer_cast(const std::shared_ptr<U> & r ) BOOST_SP_NOEXCEPT
  {
      (void) reinterpret_cast< T* >( static_cast< U* >( 0 ) );
  
      typedef typename std::shared_ptr<T>::element_type E;
  
      E * p = reinterpret_cast< E* >( r.get() );
      return std::shared_ptr<T>( r, p );
  }
  
  //static_pointer_cast overload for std::unique_ptr
  template<class T, class U> std::unique_ptr<T> static_pointer_cast( std::unique_ptr<U> && r ) BOOST_SP_NOEXCEPT
  {
      (void) static_cast< T* >( static_cast< U* >( 0 ) );
  
      typedef typename std::unique_ptr<T>::element_type E;
  
      return std::unique_ptr<T>( static_cast<E*>( r.release() ) );
  }
  
  //dynamic_pointer_cast overload for std::unique_ptr
  template<class T, class U> std::unique_ptr<T> dynamic_pointer_cast( std::unique_ptr<U> && r ) BOOST_SP_NOEXCEPT
  {
      (void) dynamic_cast< T* >( static_cast< U* >( 0 ) );
  
      BOOST_STATIC_ASSERT_MSG( boost::has_virtual_destructor<T>::value, "The target of dynamic_pointer_cast must have a virtual destructor." );
  
      T * p = dynamic_cast<T*>( r.get() );
      if( p ) r.release();
      return std::unique_ptr<T>( p );
  }
  
  //const_pointer_cast overload for std::unique_ptr
  template<class T, class U> std::unique_ptr<T> const_pointer_cast( std::unique_ptr<U> && r ) BOOST_SP_NOEXCEPT
  {
      (void) const_cast< T* >( static_cast< U* >( 0 ) );
  
      typedef typename std::unique_ptr<T>::element_type E;
  
      return std::unique_ptr<T>( const_cast<E*>( r.release() ) );
  }
  
  //reinterpret_pointer_cast overload for std::unique_ptr
  template<class T, class U> std::unique_ptr<T> reinterpret_pointer_cast( std::unique_ptr<U> && r ) BOOST_SP_NOEXCEPT
  {
      (void) reinterpret_cast< T* >( static_cast< U* >( 0 ) );
  
      typedef typename std::unique_ptr<T>::element_type E;
  
      return std::unique_ptr<T>( reinterpret_cast<E*>( r.release() ) );
  }
  
  } // namespace boost
  
  #endif // #if !defined( BOOST_NO_CXX11_SMART_PTR )
  
  #endif   //BOOST_POINTER_CAST_HPP
  