boost/ptr_container/clone_allocator.hpp

   1 //
   2 // Boost.Pointer Container
   3 //
   4 //  Copyright Thorsten Ottosen 2003-2005. Use, modification and
   5 //  distribution is subject to the Boost Software License, Version
   6 //  1.0. (See accompanying file LICENSE_1_0.txt or copy at
   7 //  http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // For more information, see http://www.boost.org/libs/ptr_container/
  10 //
  11
  12 #ifndef BOOST_PTR_CONTAINER_CLONE_ALLOCATOR_HPP
  13 #define BOOST_PTR_CONTAINER_CLONE_ALLOCATOR_HPP
  14
  15 #include <boost/assert.hpp>
  16 #include <boost/checked_delete.hpp>
  17 #include <typeinfo>
  18
  19 namespace boost
  20 {
  21     /////////////////////////////////////////////////////////////////////////
  22     // Clonable concept
  23     /////////////////////////////////////////////////////////////////////////
  24
  25     template< class T >
  26     inline T* new_clone( const T& r )
  27     {
  28         //
  29         // @remark: if you get a compile-error here,
  30         //          it is most likely because you did not
  31         //          define new_clone( const T& ) in the namespace
  32         //          of T.
  33         //
  34         T* res = new T( r );
  35         BOOST_ASSERT( typeid(r) == typeid(*res) &&
  36                       "Default new_clone() sliced object!" );
  37         return res;
  38     }
  39
  40     template< class T >
  41     inline T* new_clone( const T* r )
  42     {
  43         return r ? new_clone( *r ) : 0;
  44     }
  45
  46     //
  47     // @remark: to make new_clone() work
  48     //          with scope_ptr/shared_ptr ect.
  49     //          simply overload for those types
  50     //          in the appropriate namespace.
  51     //
  52
  53     template< class T >
  54     inline void delete_clone( const T* r )
  55     {
  56         checked_delete( r );
  57     }
  58
  59     /////////////////////////////////////////////////////////////////////////
  60     // CloneAllocator concept
  61     /////////////////////////////////////////////////////////////////////////
  62
  63     struct heap_clone_allocator
  64     {
  65         template< class U >
  66         static U* allocate_clone( const U& r )
  67         {
  68             return new_clone( r );
  69         }
  70
  71         template< class U >
  72         static void deallocate_clone( const U* r )
  73         {
  74             delete_clone( r );
  75         }
  76
  77     };
  78
  79
  80
  81     struct view_clone_allocator
  82     {
  83         template< class U >
  84         static U* allocate_clone( const U& r )
  85         {
  86             return const_cast<U*>(&r);
  87         }
  88
  89         template< class U >
  90         static void deallocate_clone( const U* /*r*/ )
  91         {
  92             // do nothing
  93         }
  94     };
  95
  96 } // namespace 'boost'
  97
  98 #endif
  99