diff options
Diffstat (limited to 'contrib/libstdc++/include/bits/gslice.h')
| -rw-r--r-- | contrib/libstdc++/include/bits/gslice.h | 125 |
1 files changed, 83 insertions, 42 deletions
diff --git a/contrib/libstdc++/include/bits/gslice.h b/contrib/libstdc++/include/bits/gslice.h index 95781f9bbcc2..78f8a67146be 100644 --- a/contrib/libstdc++/include/bits/gslice.h +++ b/contrib/libstdc++/include/bits/gslice.h @@ -1,6 +1,7 @@ // The template and inlines for the -*- C++ -*- gslice class. -// Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. +// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004 +// Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the @@ -34,61 +35,101 @@ * You should not attempt to use it directly. */ -#ifndef _CPP_BITS_GSLICE_H -#define _CPP_BITS_GSLICE_H 1 +#ifndef _GSLICE_H +#define _GSLICE_H 1 #pragma GCC system_header namespace std { - + + /** + * @brief Class defining multi-dimensional subset of an array. + * + * The slice class represents a multi-dimensional subset of an array, + * specified by three parameter sets: start offset, size array, and stride + * array. The start offset is the index of the first element of the array + * that is part of the subset. The size and stride array describe each + * dimension of the slice. Size is the number of elements in that + * dimension, and stride is the distance in the array between successive + * elements in that dimension. Each dimension's size and stride is taken + * to begin at an array element described by the previous dimension. The + * size array and stride array must be the same size. + * + * For example, if you have offset==3, stride[0]==11, size[1]==3, + * stride[1]==3, then slice[0,0]==array[3], slice[0,1]==array[6], + * slice[0,2]==array[9], slice[1,0]==array[14], slice[1,1]==array[17], + * slice[1,2]==array[20]. + */ class gslice { public: - gslice (); - gslice (size_t, const valarray<size_t>&, const valarray<size_t>&); - // XXX: the IS says the copy-ctor and copy-assignment operators are - // synthetized by the compiler but they are just unsuitable - // for a ref-counted semantic - gslice(const gslice&); - ~gslice(); - - // XXX: See the note above. - gslice& operator= (const gslice&); - - size_t start () const; - valarray<size_t> size () const; - valarray<size_t> stride () const; - + /// Construct an empty slice. + gslice (); + + /** + * @brief Construct a slice. + * + * Constructs a slice with as many dimensions as the length of the @a l + * and @a s arrays. + * + * @param o Offset in array of first element. + * @param l Array of dimension lengths. + * @param s Array of dimension strides between array elements. + */ + gslice(size_t, const valarray<size_t>&, const valarray<size_t>&); + + // XXX: the IS says the copy-ctor and copy-assignment operators are + // synthetized by the compiler but they are just unsuitable + // for a ref-counted semantic + /// Copy constructor. + gslice(const gslice&); + + /// Destructor. + ~gslice(); + + // XXX: See the note above. + /// Assignment operator. + gslice& operator=(const gslice&); + + /// Return array offset of first slice element. + size_t start() const; + + /// Return array of sizes of slice dimensions. + valarray<size_t> size() const; + + /// Return array of array strides for each dimension. + valarray<size_t> stride() const; + private: - struct _Indexer { - size_t _M_count; - size_t _M_start; - valarray<size_t> _M_size; - valarray<size_t> _M_stride; - valarray<size_t> _M_index; - _Indexer(size_t, const valarray<size_t>&, - const valarray<size_t>&); - void _M_increment_use() { ++_M_count; } - size_t _M_decrement_use() { return --_M_count; } - }; - - _Indexer* _M_index; - - template<typename _Tp> friend class valarray; + struct _Indexer { + size_t _M_count; + size_t _M_start; + valarray<size_t> _M_size; + valarray<size_t> _M_stride; + valarray<size_t> _M_index; // Linear array of referenced indices + _Indexer(size_t, const valarray<size_t>&, + const valarray<size_t>&); + void _M_increment_use() { ++_M_count; } + size_t _M_decrement_use() { return --_M_count; } + }; + + _Indexer* _M_index; + + template<typename _Tp> friend class valarray; }; - + inline size_t gslice::start () const { return _M_index ? _M_index->_M_start : 0; } - + inline valarray<size_t> gslice::size () const { return _M_index ? _M_index->_M_size : valarray<size_t>(); } - + inline valarray<size_t> gslice::stride () const { return _M_index ? _M_index->_M_stride : valarray<size_t>(); } - + inline gslice::gslice () : _M_index(0) {} inline @@ -99,7 +140,7 @@ namespace std { inline gslice::gslice(const gslice& __g) : _M_index(__g._M_index) { if (_M_index) _M_index->_M_increment_use(); } - + inline gslice::~gslice() { if (_M_index && _M_index->_M_decrement_use() == 0) delete _M_index; } @@ -112,12 +153,12 @@ namespace std { _M_index = __g._M_index; return *this; } - - + + } // std:: -#endif /* _CPP_BITS_GSLICE_H */ +#endif /* _GSLICE_H */ // Local Variables: // mode:c++ |