ForEach.h

#ifndef DASH__ALGORITHM__FOR_EACH_H__
#define DASH__ALGORITHM__FOR_EACH_H__

#include <dash/algorithm/LocalRange.h>
#include <dash/iterator/GlobIter.h>

#include <algorithm>


namespace dash {

template <typename GlobInputIt, class UnaryFunction>
void for_each(
    const GlobInputIt& first,
    const GlobInputIt& last,
    UnaryFunction func)
{
  using iterator_traits = dash::iterator_traits<GlobInputIt>;
  static_assert(
      iterator_traits::is_global_iterator::value,
      "must be a global iterator");
  auto index_range  = dash::local_index_range(first, last);
  auto lbegin_index = index_range.begin;
  auto lend_index   = index_range.end;
  auto & team       = first.pattern().team();
  if (lbegin_index != lend_index) {
    // Pattern from global begin iterator:
    auto & pattern    = first.pattern();
    // Local range to native pointers:
    auto lrange_begin = (first + pattern.global(lbegin_index)).local();
    auto lrange_end   = lrange_begin + lend_index;
    std::for_each(lrange_begin, lrange_end, func);
  }
  team.barrier();
}

template <typename GlobInputIt, class UnaryFunctionWithIndex>
void for_each_with_index(
    const GlobInputIt& first,
    const GlobInputIt& last,
    UnaryFunctionWithIndex func)
{
  using iterator_traits = dash::iterator_traits<GlobInputIt>;
  static_assert(
      iterator_traits::is_global_iterator::value,
      "must be a global iterator");

  auto index_range  = dash::local_index_range(first, last);
  auto lbegin_index = index_range.begin;
  auto lend_index   = index_range.end;
  auto & team       = first.pattern().team();
  if (lbegin_index != lend_index) {
    // Pattern from global begin iterator:
    auto & pattern    = first.pattern();
    auto first_offset = first.pos();
    // Iterate local index range:
    for (auto lindex = lbegin_index;
         lindex != lend_index;
         ++lindex) {
      auto gindex       = pattern.global(lindex);
      auto element_it   = first + (gindex - first_offset);
      func(*(element_it.local()), gindex);
    }
  }
  team.barrier();
}

} // namespace dash

#endif // DASH__ALGORITHM__FOR_EACH_H__