Io.h

00001 /*
00002  * Tiny Vector Matrix Library
00003  * Dense Vector Matrix Libary of Tiny size using Expression Templates
00004  *
00005  * Copyright (C) 2001 - 2007 Olaf Petzold <opetzold@users.sourceforge.net>
00006  *
00007  * This library is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * This library is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with this library; if not, write to the Free Software
00019  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
00020  *
00021  * $Id: Io.h,v 1.8 2007-06-23 15:58:58 opetzold Exp $
00022  */
00023 
00024 #ifndef TVMET_IO_H
00025 #define TVMET_IO_H
00026 
00027 namespace tvmet {
00028 
00029 /**
00030  * \class IoPrintHelper Io.h "tvmet/Io.h"
00031  * \brief Determines the number of digits regarding the sign of the
00032  *        container.
00033  *        This class is nesessary due to the complex type and the
00034  *        function min(), which are not defined for this type.
00035  *        So we have to dispatch between pod and complex types
00036  *        to get an information about the extra space for signs.
00037  */
00038 template<class C>
00039 class IoPrintHelper {
00040   IoPrintHelper();
00041   IoPrintHelper(const IoPrintHelper&);
00042   IoPrintHelper& operator=(const IoPrintHelper&);
00043 
00044 private:
00045   static std::streamsize width(const C& e) {
00046     std::streamsize w = static_cast<std::streamsize>(std::log10(max(abs(e)))+1);
00047     return w > 0 ? w : 0;
00048   }
00049 
00050 public:
00051   static std::streamsize width(dispatch<true>, const C& e) {
00052     return width(e);
00053   }
00054   static std::streamsize width(dispatch<false>, const C& e) {
00055     std::streamsize w = width(e);
00056     if(min(e) < 0) return w+1;
00057     else return w;
00058   }
00059 };
00060 
00061 
00062 }
00063 
00064 #endif /* TVMET_IO_H */
00065 
00066 // Local Variables:
00067 // mode:C++
00068 // tab-width:8
00069 // End: