boost/smart_ptr/scoped_ptr.hpp

   1 #ifndef BOOST_SMART_PTR_SCOPED_PTR_HPP_INCLUDED
   2 #define BOOST_SMART_PTR_SCOPED_PTR_HPP_INCLUDED
   3
   4 //  (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
   5 //  Copyright (c) 2001, 2002 Peter Dimov
   6 //
   7 //  Distributed under the Boost Software License, Version 1.0. (See
   8 //  accompanying file LICENSE_1_0.txt or copy at
   9 //  http://www.boost.org/LICENSE_1_0.txt)
  10 //
  11 //  http://www.boost.org/libs/smart_ptr/scoped_ptr.htm
  12 //
  13
  14 #include <boost/assert.hpp>
  15 #include <boost/checked_delete.hpp>
  16 #include <boost/detail/workaround.hpp>
  17
  18 #ifndef BOOST_NO_AUTO_PTR
  19 # include <memory>          // for std::auto_ptr
  20 #endif
  21
  22 namespace boost
  23 {
  24
  25 // Debug hooks
  26
  27 #if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
  28
  29 void sp_scalar_constructor_hook(void * p);
  30 void sp_scalar_destructor_hook(void * p);
  31
  32 #endif
  33
  34 //  scoped_ptr mimics a built-in pointer except that it guarantees deletion
  35 //  of the object pointed to, either on destruction of the scoped_ptr or via
  36 //  an explicit reset(). scoped_ptr is a simple solution for simple needs;
  37 //  use shared_ptr or std::auto_ptr if your needs are more complex.
  38
  39 template<class T> class scoped_ptr // noncopyable
  40 {
  41 private:
  42
  43     T * px;
  44
  45     scoped_ptr(scoped_ptr const &);
  46     scoped_ptr & operator=(scoped_ptr const &);
  47
  48     typedef scoped_ptr<T> this_type;
  49
  50     void operator==( scoped_ptr const& ) const;
  51     void operator!=( scoped_ptr const& ) const;
  52
  53 public:
  54
  55     typedef T element_type;
  56
  57     explicit scoped_ptr( T * p = 0 ): px( p ) // never throws
  58     {
  59 #if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
  60         boost::sp_scalar_constructor_hook( px );
  61 #endif
  62     }
  63
  64 #ifndef BOOST_NO_AUTO_PTR
  65
  66     explicit scoped_ptr( std::auto_ptr<T> p ): px( p.release() ) // never throws
  67     {
  68 #if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
  69         boost::sp_scalar_constructor_hook( px );
  70 #endif
  71     }
  72
  73 #endif
  74
  75     ~scoped_ptr() // never throws
  76     {
  77 #if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
  78         boost::sp_scalar_destructor_hook( px );
  79 #endif
  80         boost::checked_delete( px );
  81     }
  82
  83     void reset(T * p = 0) // never throws
  84     {
  85         BOOST_ASSERT( p == 0 || p != px ); // catch self-reset errors
  86         this_type(p).swap(*this);
  87     }
  88
  89     T & operator*() const // never throws
  90     {
  91         BOOST_ASSERT( px != 0 );
  92         return *px;
  93     }
  94
  95     T * operator->() const // never throws
  96     {
  97         BOOST_ASSERT( px != 0 );
  98         return px;
  99     }
 100
 101     T * get() const // never throws
 102     {
 103         return px;
 104     }
 105
 106 // implicit conversion to "bool"
 107 #include <boost/smart_ptr/detail/operator_bool.hpp>
 108
 109     void swap(scoped_ptr & b) // never throws
 110     {
 111         T * tmp = b.px;
 112         b.px = px;
 113         px = tmp;
 114     }
 115 };
 116
 117 template<class T> inline void swap(scoped_ptr<T> & a, scoped_ptr<T> & b) // never throws
 118 {
 119     a.swap(b);
 120 }
 121
 122 // get_pointer(p) is a generic way to say p.get()
 123
 124 template<class T> inline T * get_pointer(scoped_ptr<T> const & p)
 125 {
 126     return p.get();
 127 }
 128
 129 } // namespace boost
 130
 131 #endif // #ifndef BOOST_SMART_PTR_SCOPED_PTR_HPP_INCLUDED