listinit.h

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// -*- C++ -*-
/***************************************************************************
 * blitz/listinit.h      Classes for initialization lists
 *
 * $Id$
 *
 * Copyright (C) 1997-2011 Todd Veldhuizen <tveldhui@acm.org>
 *
 * This file is a part of Blitz.
 *
 * Blitz is free software: you can redistribute it and/or modify 
 * it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *
 * Blitz 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public 
 * License along with Blitz.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * Suggestions:          blitz-devel@lists.sourceforge.net
 * Bugs:                 blitz-support@lists.sourceforge.net    
 *
 * For more information, please see the Blitz++ Home Page:
 *    https://sourceforge.net/projects/blitz/
 *
 ***************************************************************************/
 
/*
 * Initialization lists provide a convenient way to set the elements
 * of an array.  For example,
 *
 * Array<int,2> A(3,3);
 * A = 1, 0, 0,
 *     0, 1, 0,
 *     0, 0, 1;
 */
 
#ifndef BZ_LISTINIT_H
#define BZ_LISTINIT_H
 
namespace blitz {
 
template<typename T_numtype, typename T_iterator>
class ListInitializer {
 
public:
    ListInitializer(T_iterator iter)
        : iter_(iter)
    {
    }
 
    ListInitializer<T_numtype, T_iterator> operator,(T_numtype x)
    {
        *iter_ = x;
  ++iter_;
        return ListInitializer<T_numtype, T_iterator>(iter_);
    }
 
private:
    ListInitializer();
 
protected:
    T_iterator iter_;
};
 
template<typename T_array, typename T_iterator = _bz_typename T_array::T_numtype*>
class ListInitializationSwitch {
 
public:
    typedef _bz_typename T_array::T_numtype T_numtype;
 
    ListInitializationSwitch(const ListInitializationSwitch<T_array>& lis)
        : array_(lis.array_), value_(lis.value_), 
          wipeOnDestruct_(true)
    {
        lis.disable();
    }
 
    ListInitializationSwitch(T_array& array, T_numtype value)
        : array_(array), value_(value), wipeOnDestruct_(true)
    { }
 
    ~ListInitializationSwitch()
    {
        if (wipeOnDestruct_)
            array_.initialize(value_);
    }
 
    ListInitializer<T_numtype, T_iterator> operator,(T_numtype x)
    {
        wipeOnDestruct_ = false;
        T_iterator iter = array_.getInitializationIterator();
        *iter = value_;
  ++iter;
        //T_iterator iter2 = iter + 1;
        *iter = x;
  ++iter;
        return ListInitializer<T_numtype, T_iterator>(iter);
    }
 
    void disable() const
    {
        wipeOnDestruct_ = false;
    }
 
private:
    ListInitializationSwitch();
 
protected:
    T_array& array_;
    T_numtype value_;
    mutable bool wipeOnDestruct_;
};
 
}
 
#endif // BZ_LISTINIT_H