ios_pos_types.cpp revision 5abe6dfaae971d3c0d1c8e3349b0d2b2ae83cc97 
1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <ios_pos_types.h>
30
31namespace std {
32// Implementation of the fpos class for streams.
33
34fpos& fpos::operator+=(streamoff offs)  {
35    const streamoff new_offs = mOffs + offs;
36    if (offs > 0) {
37        if (new_offs > mOffs) {
38            mOffs = new_offs;
39        } // else overflow.
40    } else {
41        if (new_offs < mOffs) {
42            mOffs = new_offs;
43        } // else overflow or 0.
44    }
45    return *this;
46}
47
48fpos fpos::operator+(streamoff offs) const {
49    fpos pos(*this);
50    pos += offs;
51    return pos;
52}
53
54fpos fpos::operator-(streamoff offs) const {
55    fpos pos(*this);
56    pos -= offs;
57    return pos;
58}
59
60}  // namespace std
61