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.md at
// the top level directory of deal.II.
//
// ---------------------------------------------------------------------

#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