| Geant4 Cross Reference |
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
17 // * *
18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
25 //
26 //
27 // Generic identifier-creator based factory. Based on
28 // factory presented in "Modern C++ Design, Andrei Alexandrescu"
29 //
30 // Jane Tinslay, September 2006
31 //
32 #ifndef G4CREATORFACTORYT_HH
33 #define G4CREATORFACTORYT_HH
34
35 #include "globals.hh"
36 #include <map>
37
38 template <typename T, typename Identifier, typename Creator>
39 class G4CreatorFactoryT {
40
41 public:
42
43 // Constructor
44 G4CreatorFactoryT();
45
46 // Destructor
47 virtual ~G4CreatorFactoryT();
48
49 // Register identifier<->creator pairs
50 G4bool Register(const Identifier& id, Creator creator);
51
52 // Create product with given identifier
53 T* Create(const Identifier& id) const;
54
55 private:
56
57 typedef std::map<Identifier, Creator> Map;
58
59 // Data member
60 Map fMap;
61
62 };
63
64 template <typename T, typename Identifier, typename Creator>
65 G4CreatorFactoryT<T, Identifier, Creator>::G4CreatorFactoryT() {}
66
67 template <typename T, typename Identifier, typename Creator>
68 G4CreatorFactoryT<T, Identifier, Creator>::~G4CreatorFactoryT() {}
69
70 template <typename T, typename Identifier, typename Creator>
71 G4bool
72 G4CreatorFactoryT<T, Identifier, Creator>::Register(const Identifier& id,
73 Creator creator)
74 {
75 if (fMap.find(id) != fMap.end()) {
76 G4ExceptionDescription ed;
77 ed << "Creator with identifier "<<id<<" already exists."<<G4endl;
78 G4Exception
79 ("G4CreatorFactoryT::Register(const Identifier& id, Creator creator)",
80 "greps0102", JustWarning, ed,
81 "Creator exists");
82 return false;
83 }
84
85 // Insert identifier<->creator pair into map
86 std::pair<Identifier, Creator> myPair(id, creator);
87 return fMap.insert(myPair).second;
88 }
89
90 template <typename T, typename Identifier, typename Creator>
91 T*
92 G4CreatorFactoryT<T, Identifier, Creator>::Create(const Identifier& id) const
93 {
94 typename Map::const_iterator iter = fMap.find(id);
95
96 if (iter == fMap.end()) {
97 G4ExceptionDescription ed;
98 ed << "Identifier "<<id<<" does not exist."<<G4endl;
99 G4Exception("G4CreatorFactoryT::Create(const Identifier& id)",
100 "greps0103", JustWarning, ed,
101 "Non-existent identifier");
102 return 0;
103 }
104
105 return iter->second();
106 }
107
108 #endif
109