src/common/ref-ptr.h
changeset 51 6642b907ba2c
parent 50 c6cbcbd6ea97
child 52 72a52d59ee9f
equal deleted inserted replaced
50:c6cbcbd6ea97 51:6642b907ba2c
     1 /* -*-	Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
       
     2 /*
       
     3  * Copyright (c) 2005,2006 INRIA
       
     4  * All rights reserved.
       
     5  *
       
     6  * This program is free software; you can redistribute it and/or modify
       
     7  * it under the terms of the GNU General Public License version 2 as
       
     8  * published by the Free Software Foundation;
       
     9  *
       
    10  * This program is distributed in the hope that it will be useful,
       
    11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
       
    12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
       
    13  * GNU General Public License for more details.
       
    14  *
       
    15  * You should have received a copy of the GNU General Public License
       
    16  * along with this program; if not, write to the Free Software
       
    17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
       
    18  *
       
    19  * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
       
    20  */
       
    21 
       
    22 #ifndef REF_PTR_H
       
    23 #define REF_PTR_H
       
    24 
       
    25 namespace ns3 {
       
    26 
       
    27 template <typename T>
       
    28 class RefPtr {
       
    29 private:
       
    30 	T *m_env;
       
    31 public:
       
    32 	RefPtr () 
       
    33 		: m_env (0) 
       
    34 	{}
       
    35 
       
    36 	RefPtr (T *env) 
       
    37 		: m_env (env) 
       
    38 	{}
       
    39 	RefPtr (RefPtr const&o) 
       
    40 		: m_env (o.m_env)
       
    41 	{
       
    42 		if (m_env != 0) {
       
    43 			m_env->m_count++;
       
    44 		}
       
    45 	}
       
    46 	// allow conversions from T to T const.
       
    47 	template <typename U>
       
    48 	RefPtr (RefPtr<U> const &o)
       
    49 		: m_env (o.peek ())
       
    50 	{
       
    51 		if (m_env != 0) {
       
    52 			m_env->m_count++;
       
    53 		}
       
    54 	}
       
    55 	~RefPtr () 
       
    56 	{
       
    57 		if (m_env != 0) {
       
    58 			m_env->m_count--;
       
    59 			if (m_env->m_count == 0) {
       
    60 				m_env->destroy ();
       
    61 			}
       
    62 		}
       
    63 	}
       
    64 	RefPtr &operator = (RefPtr const& o) 
       
    65 	{
       
    66 		if (o.m_env != 0) {
       
    67 			o.m_env->m_count++;
       
    68 		}
       
    69 		if (m_env != 0) {
       
    70 			m_env->m_count--;
       
    71 			if (m_env->m_count == 0) {
       
    72 				m_env->destroy ();
       
    73 			}
       
    74 		}
       
    75 		m_env = o.m_env;
       
    76 		return *this;
       
    77 	}
       
    78 	T *operator -> () 
       
    79 	{
       
    80 		return m_env;
       
    81 	}
       
    82 	T *operator -> () const
       
    83 	{
       
    84 		return m_env;
       
    85 	}
       
    86 	// allow if (!sp)
       
    87 	bool operator! () 
       
    88 	{
       
    89 		return m_env == 0;
       
    90 	}
       
    91 private:
       
    92 	class Tester {
       
    93 	private:
       
    94 		void operator delete (void *);
       
    95 	};
       
    96 public:
       
    97 	// allow if (sp)
       
    98 	operator Tester * () const
       
    99 	{
       
   100 		if (m_env == 0) {
       
   101 			return 0;
       
   102 		}
       
   103 		static Tester test;
       
   104 		return &test;
       
   105 	}
       
   106 	// allow if (sp == 0)
       
   107 	inline friend bool operator == (RefPtr const &lhs, T const *rhs)
       
   108 	{
       
   109 		return lhs.m_env == rhs;
       
   110 	}
       
   111 	// allow if (0 == sp)
       
   112 	inline friend bool operator == (T const *lhs, RefPtr &rhs)
       
   113 	{
       
   114 		return lhs == rhs.m_env;
       
   115 	}
       
   116 	// allow if (sp != 0)
       
   117 	inline friend bool operator != (RefPtr const &lhs, T const *rhs)
       
   118 	{
       
   119 		return lhs.m_env != rhs;
       
   120 	}
       
   121 	// allow if (0 != sp)
       
   122 	inline friend bool operator != (T const *lhs, RefPtr &rhs)
       
   123 	{
       
   124 		return lhs != rhs.m_env;
       
   125 	}
       
   126 	
       
   127 	T *peek (void) 
       
   128 	{
       
   129 		return m_env;
       
   130 	}
       
   131 	T *peek (void) const
       
   132 	{
       
   133 		return m_env;
       
   134 	}
       
   135 };
       
   136 
       
   137 }; // namespace ns3
       
   138 
       
   139 #endif /* REF_PTR_H */