boost/signals2/deconstruct_ptr.hpp

   1 // DEPRECATED in favor of adl_postconstruct and adl_predestruct with
   2 // deconstruct<T>().
   3 // A factory function for creating a shared_ptr that enhances the plain
   4 // shared_ptr constructors by adding support for postconstructors
   5 // and predestructors through the boost::signals2::postconstructible and
   6 // boost::signals2::predestructible base classes.
   7 //
   8 // Copyright Frank Mori Hess 2007-2008.
   9 //
  10 // Use, modification and
  11 // distribution is subject to the Boost Software License, Version
  12 // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  13 // http://www.boost.org/LICENSE_1_0.txt)
  14
  15 #ifndef BOOST_SIGNALS2_DECONSTRUCT_PTR_HPP
  16 #define BOOST_SIGNALS2_DECONSTRUCT_PTR_HPP
  17
  18 #include <boost/assert.hpp>
  19 #include <boost/checked_delete.hpp>
  20 #include <boost/signals2/postconstructible.hpp>
  21 #include <boost/signals2/predestructible.hpp>
  22 #include <boost/shared_ptr.hpp>
  23
  24 namespace boost
  25 {
  26   namespace signals2
  27   {
  28     namespace detail
  29     {
  30       extern inline void do_postconstruct(const postconstructible *ptr)
  31       {
  32         postconstructible *nonconst_ptr = const_cast<postconstructible*>(ptr);
  33         nonconst_ptr->postconstruct();
  34       }
  35       extern inline void do_postconstruct(...)
  36       {
  37       }
  38       extern inline void do_predestruct(...)
  39       {
  40       }
  41       extern inline void do_predestruct(const predestructible *ptr)
  42       {
  43         try
  44         {
  45           predestructible *nonconst_ptr = const_cast<predestructible*>(ptr);
  46           nonconst_ptr->predestruct();
  47         }
  48         catch(...)
  49         {
  50           BOOST_ASSERT(false);
  51         }
  52       }
  53     }
  54
  55     template<typename T> class predestructing_deleter
  56     {
  57     public:
  58       void operator()(const T *ptr) const
  59       {
  60         detail::do_predestruct(ptr);
  61         checked_delete(ptr);
  62       }
  63     };
  64
  65     template<typename T>
  66     shared_ptr<T> deconstruct_ptr(T *ptr)
  67     {
  68       if(ptr == 0) return shared_ptr<T>(ptr);
  69       shared_ptr<T> shared(ptr, boost::signals2::predestructing_deleter<T>());
  70       detail::do_postconstruct(ptr);
  71       return shared;
  72     }
  73     template<typename T, typename D>
  74     shared_ptr<T> deconstruct_ptr(T *ptr, D deleter)
  75     {
  76       shared_ptr<T> shared(ptr, deleter);
  77       if(ptr == 0) return shared;
  78       detail::do_postconstruct(ptr);
  79       return shared;
  80     }
  81   }
  82 }
  83
  84 #endif // BOOST_SIGNALS2_DECONSTRUCT_PTR_HPP