1// The template and inlines for the -*- C++ -*- gslice class.
2
3// Copyright (C) 1997-1999 Cygnus Solutions
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 2, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14// GNU General Public License for more details.
15
16// You should have received a copy of the GNU General Public License along
17// with this library; see the file COPYING.  If not, write to the Free
18// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19// USA.
20
21// As a special exception, you may use this file as part of a free software
22// library without restriction.  Specifically, if other files instantiate
23// templates or use macros or inline functions from this file, or you compile
24// this file and link it with other files to produce an executable, this
25// file does not by itself cause the resulting executable to be covered by
26// the GNU General Public License.  This exception does not however
27// invalidate any other reasons why the executable file might be covered by
28// the GNU General Public License.
29
30// Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
31
32#ifndef __GSLICE__
33#define __GSLICE__
34
35extern "C++" {
36
37struct _Indexer {
38    size_t _M_count;
39    size_t _M_start;
40    valarray<size_t> _M_size;
41    valarray<size_t> _M_stride;
42    valarray<size_t> _M_index;
43    _Indexer(size_t, const valarray<size_t>&, const valarray<size_t>&);
44    void _M_increment_use() { ++_M_count; }
45    size_t _M_decrement_use() { return --_M_count; }
46};
47
48
49class gslice
50{
51public:
52    gslice ();
53    gslice (size_t, const valarray<size_t>&, const valarray<size_t>&);
54    gslice(const gslice&);
55    ~gslice();
56
57    gslice& operator= (const gslice&);
58    size_t           start () const;
59    valarray<size_t> size () const;
60    valarray<size_t> stride () const;
61
62private:
63    _Indexer* _M_index;
64
65    template<typename _Tp> friend class valarray;
66};
67
68inline size_t
69gslice::start () const
70{ return _M_index ? _M_index->_M_start : 0; }
71
72inline valarray<size_t>
73gslice::size () const
74{ return _M_index ? _M_index->_M_size : valarray<size_t>(); }
75
76inline valarray<size_t>
77gslice::stride () const
78{ return _M_index ? _M_index->_M_stride : valarray<size_t>(); }
79
80inline gslice::gslice () : _M_index(0) {}
81
82inline
83gslice::gslice(size_t __o, const valarray<size_t>& __l,
84               const valarray<size_t>& __s)
85        : _M_index(new _Indexer(__o, __l, __s)) {}
86
87inline
88gslice::gslice(const gslice& __g) : _M_index(__g._M_index)
89{ if (_M_index) _M_index->_M_increment_use(); }
90
91inline
92gslice::~gslice()
93{ if (_M_index && _M_index->_M_decrement_use() == 0) delete _M_index; }
94
95inline gslice&
96gslice::operator= (const gslice& __g)
97{
98    if (__g._M_index) __g._M_index->_M_increment_use();
99    if (_M_index && _M_index->_M_decrement_use() == 0) delete _M_index;
100    _M_index = __g._M_index;
101    return *this;
102}
103
104
105} // extern "C++"
106
107#endif // __GSLICE__
108
109// Local Variables:
110// mode:c++
111// End:
112