#ifndef __GSLICE__
#define __GSLICE__
extern "C++" {
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; }
};
class gslice
{
public:
gslice ();
gslice (size_t, const valarray<size_t>&, const valarray<size_t>&);
gslice(const gslice&);
~gslice();
gslice& operator= (const gslice&);
size_t start () const;
valarray<size_t> size () const;
valarray<size_t> stride () const;
private:
_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
gslice::gslice(size_t __o, const valarray<size_t>& __l,
const valarray<size_t>& __s)
: _M_index(new _Indexer(__o, __l, __s)) {}
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; }
inline gslice&
gslice::operator= (const gslice& __g)
{
if (__g._M_index) __g._M_index->_M_increment_use();
if (_M_index && _M_index->_M_decrement_use() == 0) delete _M_index;
_M_index = __g._M_index;
return *this;
}
}
#endif // __GSLICE__