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 35 extern "C++" { 36 37 struct _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 49 class gslice 50 { 51 public: 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 62 private: 63 _Indexer* _M_index; 64 65 template<typename _Tp> friend class valarray; 66 }; 67 68 inline size_t 69 gslice::start () const 70 { return _M_index ? _M_index->_M_start : 0; } 71 72 inline valarray<size_t> 73 gslice::size () const 74 { return _M_index ? _M_index->_M_size : valarray<size_t>(); } 75 76 inline valarray<size_t> 77 gslice::stride () const 78 { return _M_index ? _M_index->_M_stride : valarray<size_t>(); } 79 80 inline gslice::gslice () : _M_index(0) {} 81 82 inline 83 gslice::gslice(size_t __o, const valarray<size_t>& __l, 84 const valarray<size_t>& __s) 85 : _M_index(new _Indexer(__o, __l, __s)) {} 86 87 inline 88 gslice::gslice(const gslice& __g) : _M_index(__g._M_index) 89 { if (_M_index) _M_index->_M_increment_use(); } 90 91 inline 92 gslice::~gslice() 93 { if (_M_index && _M_index->_M_decrement_use() == 0) delete _M_index; } 94 95 inline gslice& 96 gslice::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