1// Ceres Solver - A fast non-linear least squares minimizer
2// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
3// http://code.google.com/p/ceres-solver/
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// * Redistributions of source code must retain the above copyright notice,
9//   this list of conditions and the following disclaimer.
10// * 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// * Neither the name of Google Inc. nor the names of its contributors may be
14//   used to endorse or promote products derived from this software without
15//   specific prior written permission.
16//
17// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27// POSSIBILITY OF SUCH DAMAGE.
28//
29// Author: keir@google.com (Keir Mierle)
30
31#ifndef CERES_INTERNAL_STL_UTIL_H_
32#define CERES_INTERNAL_STL_UTIL_H_
33
34#include <algorithm>
35
36namespace ceres {
37
38// STLDeleteContainerPointers()
39//  For a range within a container of pointers, calls delete
40//  (non-array version) on these pointers.
41// NOTE: for these three functions, we could just implement a DeleteObject
42// functor and then call for_each() on the range and functor, but this
43// requires us to pull in all of algorithm.h, which seems expensive.
44// For hash_[multi]set, it is important that this deletes behind the iterator
45// because the hash_set may call the hash function on the iterator when it is
46// advanced, which could result in the hash function trying to deference a
47// stale pointer.
48template <class ForwardIterator>
49void STLDeleteContainerPointers(ForwardIterator begin,
50                                ForwardIterator end) {
51  while (begin != end) {
52    ForwardIterator temp = begin;
53    ++begin;
54    delete *temp;
55  }
56}
57
58// Variant of STLDeleteContainerPointers which allows the container to
59// contain duplicates.
60template <class ForwardIterator>
61void STLDeleteUniqueContainerPointers(ForwardIterator begin,
62                                      ForwardIterator end) {
63  sort(begin, end);
64  ForwardIterator new_end = unique(begin, end);
65  while (begin != new_end) {
66    ForwardIterator temp = begin;
67    ++begin;
68    delete *temp;
69  }
70}
71
72// STLDeleteElements() deletes all the elements in an STL container and clears
73// the container.  This function is suitable for use with a vector, set,
74// hash_set, or any other STL container which defines sensible begin(), end(),
75// and clear() methods.
76//
77// If container is NULL, this function is a no-op.
78//
79// As an alternative to calling STLDeleteElements() directly, consider
80// ElementDeleter (defined below), which ensures that your container's elements
81// are deleted when the ElementDeleter goes out of scope.
82template <class T>
83void STLDeleteElements(T *container) {
84  if (!container) return;
85  STLDeleteContainerPointers(container->begin(), container->end());
86  container->clear();
87}
88
89}  // namespace ceres
90
91#endif  // CERES_INTERNAL_STL_UTIL_H_
92