synchronous_iterator.h

// ---------------------------------------------------------------------
//
// Copyright (C) 2008 - 2018 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, 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 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE at
// the top level of the deal.II distribution.
//
// ---------------------------------------------------------------------

#ifndef dealii_synchronous_iterator_h
#define dealii_synchronous_iterator_h


#include <deal.II/base/config.h>
#include <deal.II/base/exceptions.h>


#include <iterator>
#include <tuple>

DEAL_II_NAMESPACE_OPEN

template <typename Iterators>
struct SynchronousIterators
{
  SynchronousIterators (const Iterators &i);

  const Iterators &operator* () const;

  Iterators &operator* ();

private:
  Iterators iterators;
};



template <typename Iterators>
inline
SynchronousIterators<Iterators>::
SynchronousIterators (const Iterators &i)
  :
  iterators (i)
{}



template <typename Iterators>
inline
const Iterators &
SynchronousIterators<Iterators>::operator* () const
{
  return iterators;
}



template <typename Iterators>
inline
Iterators &
SynchronousIterators<Iterators>::operator* ()
{
  return iterators;
}



template <typename Iterators>
inline
bool
operator< (const SynchronousIterators<Iterators> &a,
           const SynchronousIterators<Iterators> &b)
{
  return std::get<0>(*a) < std::get<0>(*b);
}



template <typename Iterators>
inline
std::size_t
operator- (const SynchronousIterators<Iterators> &a,
           const SynchronousIterators<Iterators> &b)
{
  Assert (std::distance (std::get<0>(*b),
                         std::get<0>(*a)) >= 0,
          ExcInternalError());
  return std::distance (std::get<0>(*b),
                        std::get<0>(*a));
}


template <typename I1, typename I2>
inline
void advance (std::tuple<I1,I2> &t,
              const unsigned int       n)
{
  std::advance (std::get<0>(t), n);
  std::advance (std::get<1>(t), n);
}

template <typename I1, typename I2, typename I3>
inline
void advance (std::tuple<I1,I2,I3> &t,
              const unsigned int          n)
{
  std::advance (std::get<0>(t), n);
  std::advance (std::get<1>(t), n);
  std::advance (std::get<2>(t), n);
}

template <typename I1, typename I2,
          typename I3, typename I4>
inline
void advance (std::tuple<I1,I2,I3, I4> &t,
              const unsigned int              n)
{
  std::advance (std::get<0>(t), n);
  std::advance (std::get<1>(t), n);
  std::advance (std::get<2>(t), n);
  std::advance (std::get<3>(t), n);
}



template <typename I1, typename I2>
inline
void advance_by_one (std::tuple<I1,I2> &t)
{
  ++std::get<0>(t);
  ++std::get<1>(t);
}

template <typename I1, typename I2, typename I3>
inline
void advance_by_one (std::tuple<I1,I2,I3> &t)
{
  ++std::get<0>(t);
  ++std::get<1>(t);
  ++std::get<2>(t);
}

template <typename I1, typename I2,
          typename I3, typename I4>
inline
void advance_by_one (std::tuple<I1,I2,I3,I4> &t)
{
  ++std::get<0>(t);
  ++std::get<1>(t);
  ++std::get<2>(t);
  ++std::get<3>(t);
}



template <typename Iterators>
inline
SynchronousIterators<Iterators>
operator + (const SynchronousIterators<Iterators> &a,
            const std::size_t                      n)
{
  SynchronousIterators<Iterators> x (a);
  ::advance (*x, n);
  return x;
}

template <typename Iterators>
inline
SynchronousIterators<Iterators>
operator ++ (SynchronousIterators<Iterators> &a)
{
  ::advance_by_one (*a);
  return a;
}


template <typename Iterators>
inline
bool
operator != (const SynchronousIterators<Iterators> &a,
             const SynchronousIterators<Iterators> &b)
{
  return (std::get<0>(*a) !=
          std::get<0>(*b));
}

DEAL_II_NAMESPACE_CLOSE

#endif