boost/ptr_container/detail/default_deleter.hpp

   1 // (C) Copyright Jonathan Turkanis 2004-2005.
   2 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
   4
   5 // Contains the definition of move_ptrs::default_deleter, the default
   6 // Deleter template argument to move_ptr. Uses a technique of Daniel
   7 // Wallin to capture the type of a pointer at the time the deleter
   8 // is constructed, so that move_ptrs can delete objects of incomplete
   9 // type by default.
  10
  11 #ifndef BOOST_MOVE_PTR_DEFAULT_DELETER_HPP_INCLUDED
  12 #define BOOST_MOVE_PTR_DEFAULT_DELETER_HPP_INCLUDED
  13
  14 #include <boost/checked_delete.hpp>
  15 #include <boost/mpl/if.hpp>
  16 #include <boost/type_traits/is_array.hpp>
  17 #include <boost/type_traits/remove_bounds.hpp>
  18
  19 namespace boost { namespace ptr_container_detail { namespace move_ptrs {
  20
  21 namespace ptr_container_detail {
  22
  23 template<typename T>
  24 struct deleter_base {
  25     typedef void (*deleter)(T*);
  26     deleter_base(deleter d) { delete_ = d; }
  27     void operator() (T* t) const { delete_(t); }
  28     static deleter delete_;
  29 };
  30
  31 template<class T>
  32 typename deleter_base<T>::deleter
  33 deleter_base<T>::delete_;
  34
  35 template<typename T>
  36 struct scalar_deleter : deleter_base<T> {
  37     typedef deleter_base<T> base;
  38     scalar_deleter() : base(do_delete) { }
  39     static void do_delete(T* t) { checked_delete(t); }
  40 };
  41
  42 template<typename T>
  43 struct array_deleter
  44     : deleter_base<typename remove_bounds<T>::type>
  45 {
  46     typedef typename remove_bounds<T>::type element_type;
  47     typedef deleter_base<element_type> base;
  48     array_deleter() : base(do_delete) { }
  49     static void do_delete(element_type* t) { checked_array_delete(t); }
  50 };
  51
  52 } // End namespace ptr_container_detail.
  53
  54 template<typename T>
  55 struct default_deleter
  56     : mpl::if_<
  57           is_array<T>,
  58           ptr_container_detail::array_deleter<T>,
  59           ptr_container_detail::scalar_deleter<T>
  60       >::type
  61 {
  62     default_deleter() { }
  63     template<typename TT>
  64     default_deleter(default_deleter<TT> tt) { }
  65 };
  66
  67 } } } // End namespaces ptr_container_detail, move_ptrs, boost.
  68
  69 #endif // #ifndef BOOST_MOVE_PTR_DEFAULT_DELETER_HPP_INCLUDED