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QoreNodeEvalOptionalRefHolder.h
1 /* -*- mode: c++; indent-tabs-mode: nil -*- */
2 /*
3  QoreNodeEvalOptionalRefHolder.h
4 
5  Qore Programming Language
6 
7  Copyright 2003 - 2013 David Nichols
8 
9  This library is free software; you can redistribute it and/or
10  modify it under the terms of the GNU Lesser General Public
11  License as published by the Free Software Foundation; either
12  version 2.1 of the License, or (at your option) any later version.
13 
14  This library is distributed in the hope that it will be useful,
15  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  Lesser General Public License for more details.
18 
19  You should have received a copy of the GNU Lesser General Public
20  License along with this library; if not, write to the Free Software
21  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23 
24 #ifndef _QORE_QORENODEEVALOPTIONALREFHOLDER_H
25 
26 #define _QORE_QORENODEEVALOPTIONALREFHOLDER_H
27 
29 
38  private:
39  AbstractQoreNode *val;
40  ExceptionSink *xsink;
41  bool needs_deref;
42 
43  DLLLOCAL void discard_intern() {
44  if (needs_deref && val)
45  val->deref(xsink);
46  }
47 
50 
52  DLLLOCAL QoreNodeEvalOptionalRefHolder& operator=(const QoreNodeEvalOptionalRefHolder&);
53 
55 
57  DLLLOCAL void *operator new(size_t);
58 
59  public:
61  DLLLOCAL QoreNodeEvalOptionalRefHolder(ExceptionSink *n_xsink) : val(0), xsink(n_xsink), needs_deref(false) {
62  }
63 
65  DLLLOCAL QoreNodeEvalOptionalRefHolder(const AbstractQoreNode *exp, ExceptionSink *n_xsink) : xsink(n_xsink) {
66  if (exp)
67  val = exp->eval(needs_deref, xsink);
68  else {
69  val = 0;
70  needs_deref = false;
71  }
72  }
73 
76  discard_intern();
77  }
78 
80  DLLLOCAL void discard() {
81  discard_intern();
82  needs_deref = false;
83  val = 0;
84  }
85 
87  DLLLOCAL void assign(bool n_needs_deref, AbstractQoreNode *n_val) {
88  discard_intern();
89  needs_deref = n_needs_deref;
90  val = n_val;
91  }
92 
95  if (needs_deref)
96  needs_deref = false;
97  else if (val)
98  val->ref();
99  return val;
100  }
101 
103  DLLLOCAL const AbstractQoreNode *operator->() const { return val; }
104 
106  DLLLOCAL const AbstractQoreNode *operator*() const { return val; }
107 
109  DLLLOCAL operator bool() const { return val != 0; }
110 
112  DLLLOCAL bool isTemp() const { return needs_deref; }
113 
114 };
115 
116 #endif