valarray_after.h

symbian上STL模板库的实现

// The template and inlines for the -*- C++ -*- internal _Meta class.

// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003 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
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

// Written by Gabriel Dos Reis <[e-mail]>

/** @file valarray_meta.h
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

#ifndef _VALARRAY_AFTER_H
#define _VALARRAY_AFTER_H 1

//#pragma GCC system_header

namespace std
{

    //
    // gslice_array closure.
    //
    template<class _Dom> class _GBase {
        public:
            typedef typename _Dom::value_type value_type;

            _GBase (const _Dom& __e, const valarray<size_t>& __i)
                : _M_expr (__e), _M_index(__i) {}
            value_type operator[] (size_t __i) const
            { return _M_expr[_M_index[__i]]; }
            size_t size () const { return _M_index.size(); }

        private:
            const _Dom&	 _M_expr;
            const valarray<size_t>& _M_index;
    };

    template<typename _Tp> class _GBase<_Array<_Tp> > {
        public:
            typedef _Tp value_type;

            _GBase (_Array<_Tp> __a, const valarray<size_t>& __i)
                : _M_array (__a), _M_index(__i) {}
            value_type operator[] (size_t __i) const
            { return _M_array._M_data[_M_index[__i]]; }
            size_t size () const { return _M_index.size(); }

        private:
            const _Array<_Tp>     _M_array;
            const valarray<size_t>& _M_index;
    };

    template<class _Dom> struct _GClos<_Expr,_Dom> : _GBase<_Dom> {
        typedef _GBase<_Dom> _Base;
        typedef typename _Base::value_type value_type;

        _GClos (const _Dom& __e, const valarray<size_t>& __i)
            : _Base (__e, __i) {}
    };

    template<typename _Tp>
        struct _GClos<_ValArray,_Tp> : _GBase<_Array<_Tp> > {
            typedef _GBase<_Array<_Tp> > _Base;
            typedef typename _Base::value_type value_type;

            _GClos (_Array<_Tp> __a, const valarray<size_t>& __i)
                : _Base (__a, __i) {}
        };

    //
    // indirect_array closure
    //
    template<class _Dom> class _IBase {
        public:
            typedef typename _Dom::value_type value_type;

            _IBase (const _Dom& __e, const valarray<size_t>& __i)
                : _M_expr (__e), _M_index (__i) {}
            value_type operator[] (size_t __i) const
            { return _M_expr[_M_index[__i]]; }
            size_t size() const { return _M_index.size(); }

        private:
            const _Dom&	    _M_expr;
            const valarray<size_t>& _M_index;
    };

    template<class _Dom> struct _IClos<_Expr,_Dom> : _IBase<_Dom> {
        typedef _IBase<_Dom> _Base;
        typedef typename _Base::value_type value_type;

        _IClos (const _Dom& __e, const valarray<size_t>& __i)
            : _Base (__e, __i) {}
    };

    template<typename _Tp>
        struct _IClos<_ValArray,_Tp>  : _IBase<valarray<_Tp> > {
            typedef _IBase<valarray<_Tp> > _Base;
            typedef _Tp value_type;

            _IClos (const valarray<_Tp>& __a, const valarray<size_t>& __i)
                : _Base (__a, __i) {}
        };

    //
    // class _Expr
    //
    template<class _Clos, typename _Tp>
        class _Expr
        {
            public:
                typedef _Tp value_type;

                _Expr(const _Clos&);

                const _Clos& operator()() const;

                value_type operator[](size_t) const;
                valarray<value_type> operator[](slice) const;
                valarray<value_type> operator[](const gslice&) const;
                valarray<value_type> operator[](const valarray<bool>&) const;
                valarray<value_type> operator[](const valarray<size_t>&) const;

                _Expr<_UnClos<__unary_plus,std::_Expr,_Clos>, value_type>
                    operator+() const;

                _Expr<_UnClos<__negate,std::_Expr,_Clos>, value_type>
                    operator-() const;

                _Expr<_UnClos<__bitwise_not,std::_Expr,_Clos>, value_type>
                    operator~() const;

                _Expr<_UnClos<__logical_not,std::_Expr,_Clos>, bool>
                    operator!() const;

                size_t size() const;
                value_type sum() const;

                valarray<value_type> shift(int) const;
                valarray<value_type> cshift(int) const;

                value_type min() const;
                value_type max() const;

                valarray<value_type> apply(value_type (*)(const value_type&)) const;
                valarray<value_type> apply(value_type (*)(value_type)) const;

            private:
                const _Clos _M_closure;
        };

    template<class _Clos, typename _Tp>
        inline
        _Expr<_Clos,_Tp>::_Expr(const _Clos& __c) : _M_closure(__c) {}

    template<class _Clos, typename _Tp>
        inline const _Clos&
        _Expr<_Clos,_Tp>::operator()() const
        { return _M_closure; }

    template<class _Clos, typename _Tp>
        inline _Tp
        _Expr<_Clos,_Tp>::operator[](size_t __i) const
        { return _M_closure[__i]; }

    template<class _Clos, typename _Tp>
        inline valarray<_Tp>
        _Expr<_Clos,_Tp>::operator[](slice __s) const
        { return _M_closure[__s]; }

    template<class _Clos, typename _Tp>
        inline valarray<_Tp>
        _Expr<_Clos,_Tp>::operator[](const gslice& __gs) const
        { return _M_closure[__gs]; }

    template<class _Clos, typename _Tp>
        inline valarray<_Tp>
        _Expr<_Clos,_Tp>::operator[](const valarray<bool>& __m) const
        { return _M_closure[__m]; }

    template<class _Clos, typename _Tp>
        inline valarray<_Tp>
        _Expr<_Clos,_Tp>::operator[](const valarray<size_t>& __i) const
        { return _M_closure[__i]; }

    template<class _Clos, typename _Tp>
        inline size_t
        _Expr<_Clos,_Tp>::size() const  { return _M_closure.size (); }

    template<class _Clos, typename _Tp>
        inline valarray<_Tp>
        _Expr<_Clos, _Tp>::shift(int __n) const
        { return valarray<_Tp>(_M_closure).shift(__n); }

    template<class _Clos, typename _Tp>
        inline valarray<_Tp>
        _Expr<_Clos, _Tp>::cshift(int __n) const
        { return valarray<_Tp>(_M_closure).cshift(__n); }

    template<class _Clos, typename _Tp>
        inline valarray<_Tp>
        _Expr<_Clos, _Tp>::apply(_Tp __f(const _Tp&)) const
        { return valarray<_Tp>(_M_closure).apply(__f); }

    template<class _Clos, typename _Tp>
        inline valarray<_Tp>
        _Expr<_Clos, _Tp>::apply(_Tp __f(_Tp)) const
        { return valarray<_Tp>(_M_closure).apply(__f); }

    // XXX: replace this with a more robust summation algorithm.
    template<class _Clos, typename _Tp>
        inline _Tp
        _Expr<_Clos,_Tp>::sum() const
        {
            size_t __n = _M_closure.size();
            if (__n == 0)
                return _Tp();
            else
            {
                _Tp __s = _M_closure[--__n];
                while (__n != 0)
                    __s += _M_closure[--__n];
                return __s;
            }
        }