Install gcc-4.3.3-tdm-1-g++.tar.gz
[msysgit.git] / mingw / lib / gcc / mingw32 / 4.3.3 / include / c++ / bits / gslice.h
blob7f305f056468c3ebbe52463e7cac88a46db49a95
1 // The template and inlines for the -*- C++ -*- gslice class.
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004, 2005, 2006
4 // Free Software Foundation, Inc.
5 //
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 2, or (at your option)
10 // any later version.
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // You should have received a copy of the GNU General Public License along
18 // with this library; see the file COPYING. If not, write to the Free
19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20 // USA.
22 // As a special exception, you may use this file as part of a free software
23 // library without restriction. Specifically, if other files instantiate
24 // templates or use macros or inline functions from this file, or you compile
25 // this file and link it with other files to produce an executable, this
26 // file does not by itself cause the resulting executable to be covered by
27 // the GNU General Public License. This exception does not however
28 // invalidate any other reasons why the executable file might be covered by
29 // the GNU General Public License.
31 /** @file gslice.h
32 * This is an internal header file, included by other library headers.
33 * You should not attempt to use it directly.
36 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
38 #ifndef _GSLICE_H
39 #define _GSLICE_H 1
41 #pragma GCC system_header
43 _GLIBCXX_BEGIN_NAMESPACE(std)
45 /**
46 * @brief Class defining multi-dimensional subset of an array.
48 * The slice class represents a multi-dimensional subset of an array,
49 * specified by three parameter sets: start offset, size array, and stride
50 * array. The start offset is the index of the first element of the array
51 * that is part of the subset. The size and stride array describe each
52 * dimension of the slice. Size is the number of elements in that
53 * dimension, and stride is the distance in the array between successive
54 * elements in that dimension. Each dimension's size and stride is taken
55 * to begin at an array element described by the previous dimension. The
56 * size array and stride array must be the same size.
58 * For example, if you have offset==3, stride[0]==11, size[1]==3,
59 * stride[1]==3, then slice[0,0]==array[3], slice[0,1]==array[6],
60 * slice[0,2]==array[9], slice[1,0]==array[14], slice[1,1]==array[17],
61 * slice[1,2]==array[20].
63 class gslice
65 public:
66 /// Construct an empty slice.
67 gslice();
69 /**
70 * @brief Construct a slice.
72 * Constructs a slice with as many dimensions as the length of the @a l
73 * and @a s arrays.
75 * @param o Offset in array of first element.
76 * @param l Array of dimension lengths.
77 * @param s Array of dimension strides between array elements.
79 gslice(size_t, const valarray<size_t>&, const valarray<size_t>&);
81 // XXX: the IS says the copy-ctor and copy-assignment operators are
82 // synthesized by the compiler but they are just unsuitable
83 // for a ref-counted semantic
84 /// Copy constructor.
85 gslice(const gslice&);
87 /// Destructor.
88 ~gslice();
90 // XXX: See the note above.
91 /// Assignment operator.
92 gslice& operator=(const gslice&);
94 /// Return array offset of first slice element.
95 size_t start() const;
97 /// Return array of sizes of slice dimensions.
98 valarray<size_t> size() const;
100 /// Return array of array strides for each dimension.
101 valarray<size_t> stride() const;
103 private:
104 struct _Indexer
106 size_t _M_count;
107 size_t _M_start;
108 valarray<size_t> _M_size;
109 valarray<size_t> _M_stride;
110 valarray<size_t> _M_index; // Linear array of referenced indices
112 _Indexer()
113 : _M_count(1), _M_start(0), _M_size(), _M_stride(), _M_index() {}
115 _Indexer(size_t, const valarray<size_t>&,
116 const valarray<size_t>&);
118 void
119 _M_increment_use()
120 { ++_M_count; }
122 size_t
123 _M_decrement_use()
124 { return --_M_count; }
127 _Indexer* _M_index;
129 template<typename _Tp> friend class valarray;
132 inline size_t
133 gslice::start() const
134 { return _M_index ? _M_index->_M_start : 0; }
136 inline valarray<size_t>
137 gslice::size() const
138 { return _M_index ? _M_index->_M_size : valarray<size_t>(); }
140 inline valarray<size_t>
141 gslice::stride() const
142 { return _M_index ? _M_index->_M_stride : valarray<size_t>(); }
144 // _GLIBCXX_RESOLVE_LIB_DEFECTS
145 // 543. valarray slice default constructor
146 inline
147 gslice::gslice()
148 : _M_index(new gslice::_Indexer()) {}
150 inline
151 gslice::gslice(size_t __o, const valarray<size_t>& __l,
152 const valarray<size_t>& __s)
153 : _M_index(new gslice::_Indexer(__o, __l, __s)) {}
155 inline
156 gslice::gslice(const gslice& __g)
157 : _M_index(__g._M_index)
158 { if (_M_index) _M_index->_M_increment_use(); }
160 inline
161 gslice::~gslice()
163 if (_M_index && _M_index->_M_decrement_use() == 0)
164 delete _M_index;
167 inline gslice&
168 gslice::operator=(const gslice& __g)
170 if (__g._M_index)
171 __g._M_index->_M_increment_use();
172 if (_M_index && _M_index->_M_decrement_use() == 0)
173 delete _M_index;
174 _M_index = __g._M_index;
175 return *this;
178 _GLIBCXX_END_NAMESPACE
180 #endif /* _GSLICE_H */