source: vscpl/src/hu/varadiistvan/scpl/io/Failable.h@ 6:53519b47b166

Last change on this file since 6:53519b47b166 was 6:53519b47b166, checked in by István Váradi <ivaradi@…>, 12 years ago

Imported some further stuff from the IO code

File size: 5.3 KB
Line 
1// Copyright (c) 2013 by István Váradi
2
3// This file is part of VSCPL, a simple cross-platform utility library
4
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions are met:
7
8// 1. Redistributions of source code must retain the above copyright notice, this
9// list of conditions and the following disclaimer.
10// 2. Redistributions in binary form must reproduce the above copyright notice,
11// this list of conditions and the following disclaimer in the documentation
12// and/or other materials provided with the distribution.
13
14// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
15// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
18// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
23// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24
25// The views and conclusions contained in the software and documentation are those
26// of the authors and should not be interpreted as representing official policies,
27// either expressed or implied, of the FreeBSD Project.
28
29#ifndef HU_VARADIISTVAN_SCPL_IO_FAILABLE_H
30#define HU_VARADIISTVAN_SCPL_IO_FAILABLE_H
31//------------------------------------------------------------------------------
32
33#include "../types.h"
34
35//------------------------------------------------------------------------------
36
37namespace hu { namespace varadiistvan { namespace scpl { namespace io {
38
39//------------------------------------------------------------------------------
40
41/**
42 * An object whose instances can fail, and the reason of the failure
43 * is indicated by an integral error code.
44 */
45class Failable
46{
47private:
48 /**
49 * The error code.
50 */
51 errorCode_t errorCode;
52
53public:
54 /**
55 * Construct the object and initialize the error code to indicate
56 * no error.
57 */
58 Failable();
59
60 /**
61 * Indicate if the object has failed.
62 */
63 bool failed() const;
64
65 /**
66 * Get the error code.
67 */
68 errorCode_t getErrorCode() const;
69
70 /**
71 * Discard the error code.
72 */
73 void repair();
74
75protected:
76 /**
77 * Set the error code.
78 */
79 void setErrorCode(errorCode_t ec);
80};
81
82//------------------------------------------------------------------------------
83
84/**
85 * An object that references another failable object and fails
86 * together with that object.
87 *
88 * The Child class should contain a function named getFailable()
89 * which returns the failable object.
90 */
91template <class Child>
92class FailableReference
93{
94public:
95 /**
96 * Indicate if the referenced object has failed.
97 */
98 bool failed() const;
99
100 /**
101 * Get the error code from the referenced object.
102 */
103 errorCode_t getErrorCode() const;
104
105 /**
106 * Discard the error code of the referenced object.
107 */
108 void repair();
109};
110
111//------------------------------------------------------------------------------
112// Inline definitions
113//------------------------------------------------------------------------------
114
115inline Failable::Failable() :
116 errorCode(XPL_NO_ERROR)
117{
118}
119
120//------------------------------------------------------------------------------
121
122inline bool Failable::failed() const
123{
124 return errorCode!=XPL_NO_ERROR;
125}
126
127//------------------------------------------------------------------------------
128
129inline errorCode_t Failable::getErrorCode() const
130{
131 return errorCode;
132}
133
134//------------------------------------------------------------------------------
135
136inline void Failable::repair()
137{
138 errorCode = XPL_NO_ERROR;
139}
140
141//------------------------------------------------------------------------------
142
143inline void Failable::setErrorCode(errorCode_t ec)
144{
145 errorCode = ec;
146}
147
148//------------------------------------------------------------------------------
149//------------------------------------------------------------------------------
150
151template <class Child>
152inline bool FailableReference<Child>::failed() const
153{
154 return static_cast<const Child*>(this)->getFailable().failed();
155}
156
157//------------------------------------------------------------------------------
158
159template <class Child>
160inline errorCode_t FailableReference<Child>::getErrorCode() const
161{
162 return static_cast<const Child*>(this)->getFailable().getErrorCode();
163}
164
165//------------------------------------------------------------------------------
166
167template <class Child>
168inline void FailableReference<Child>::repair()
169{
170 static_cast<Child*>(this)->getFailable().repair();
171}
172
173//------------------------------------------------------------------------------
174
175} /* namespace hu::varadiistvan::scpl::io */ } /* namespace hu::varadiistvan::scpl */ } /* namespace hu::varadiistvan */ } /* namespace hu */
176
177//------------------------------------------------------------------------------
178#endif // HU_VARADIISTVAN_SCPL_IO_FAILABLE_H
179
180// Local Variables:
181// mode: C++
182// c-basic-offset: 4
183// indent-tabs-mode: nil
184// End:
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