Incrementor.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: Incrementor.h,v 1.7 2007-06-23 15:58:59 opetzold Exp $
00022  */
00023 
00024 #ifndef TVMET_UTIL_INCREMENTOR_H
00025 #define TVMET_UTIL_INCREMENTOR_H
00026 
00027 namespace tvmet {
00028 
00029 namespace util {
00030 
00031 
00032 /**
00033  * \class Incrementor Incrementor.h "tvmet/util/Incrementor.h"
00034  * \brief A simple incrementor class.
00035  * The start value is given at construction time. After
00036  * each access the class increments the internal counter.
00037  * \ingroup _util_function
00038  *
00039  * \par Example:
00040  * \code
00041  * #include <algorithm>
00042  *
00043  * using namespace tvmet;
00044  *
00045  * ...
00046  *
00047  * std::generate(m1.begin(), m1.end(),
00048  * util::Incrementor<typename matrix_type::value_type>());
00049  * \endcode
00050  */
00051 template<class T>
00052 struct Incrementor
00053 {
00054   Incrementor(T start=0) : m_inc(start) { }
00055   T operator()() { m_inc+=1; return m_inc; }
00056 
00057 private:
00058   T                             m_inc;
00059 };
00060 
00061 
00062 #if defined(TVMET_HAVE_COMPLEX)
00063 /**
00064  * \class Incrementor< std::complex<T> > Incrementor.h "tvmet/util/Incrementor.h"
00065  * \brief Specialized Incrementor class.
00066  * \ingroup _util_function
00067  */
00068 template<class T>
00069 struct Incrementor< std::complex<T> > {
00070   Incrementor(const std::complex<T>& start=0)
00071     : m_inc(start) { }
00072   std::complex<T> operator()() {
00073     m_inc += std::complex<T>(1,1);
00074     return m_inc;
00075   }
00076 private:
00077   std::complex<T>                       m_inc;
00078 };
00079 #endif // defined(TVMET_HAVE_COMPLEX)
00080 
00081 
00082 } // namespace util
00083 
00084 } // namespace tvmet
00085 
00086 #endif // TVMET_UTIL_INCREMENTOR_H
00087 
00088 // Local Variables:
00089 // mode:C++
00090 // tab-width:8
00091 // End: