Chemical Data Processing Library C++ API - Version 1.1.1
Dereferencer.hpp
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1 /*
2  * Dereferencer.hpp
3  *
4  * This file is part of the Chemical Data Processing Toolkit
5  *
6  * Copyright (C) 2003 Thomas Seidel <thomas.seidel@univie.ac.at>
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public License
19  * along with this library; see the file COPYING. If not, write to
20  * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21  * Boston, MA 02111-1307, USA.
22  */
23 
29 #ifndef CDPL_UTIL_DEREFERENCER_HPP
30 #define CDPL_UTIL_DEREFERENCER_HPP
31 
32 #include "CDPL/Base/Exceptions.hpp"
33 
34 
35 namespace CDPL
36 {
37 
38  namespace Util
39  {
40 
50  template <typename ArgType, typename ResType>
51  struct Dereferencer
52  {
53 
54  public:
55  typedef ResType result_type;
56 
62  ResType operator()(const ArgType& ptr) const;
63  };
64 
74  template <typename ArgType, typename ResType>
76  {
77 
78  public:
79  typedef ResType result_type;
80 
87  ResType operator()(const ArgType& ptr) const;
88  };
89  } // namespace Util
90 } // namespace CDPL
91 
92 
93 // Implementation
94 
95 template <typename ArgType, typename ResType>
97 {
98  return *ptr;
99 }
100 
101 template <typename ArgType, typename ResType>
103 {
104  if (!ptr)
105  throw Base::NullPointerException("NullCheckDereferencer: attempt to dereference null pointer");
106 
107  return *ptr;
108 }
109 
110 #endif // CDPL_UTIL_DEREFERENCER_HPP
CDPL::Util::Dereferencer::result_type
ResType result_type
Definition: Dereferencer.hpp:55
CDPL::Util::NullCheckDereferencer
An unary functor for the dereferenciation of pointers with null pointer checking.
Definition: Dereferencer.hpp:76
CDPL::Util::Dereferencer
An unary functor for the dereferenciation of pointers without null pointer checking.
Definition: Dereferencer.hpp:52
CDPL::Util::NullCheckDereferencer::operator()
ResType operator()(const ArgType &ptr) const
Returns a reference to or copy of the pointed-to argument object.
Definition: Dereferencer.hpp:102
Exceptions.hpp
Definition of exception classes.
CDPL
The namespace of the Chemical Data Processing Library.
CDPL::Base::NullPointerException
Thrown when an operation requires or expects a valid pointer but a null pointer was provided.
Definition: Base/Exceptions.hpp:95
CDPL::Util::NullCheckDereferencer::result_type
ResType result_type
Definition: Dereferencer.hpp:79
CDPL::Util::Dereferencer::operator()
ResType operator()(const ArgType &ptr) const
Returns a reference to or copy of the pointed-to argument object.
Definition: Dereferencer.hpp:96