remote_subrange.hpp

// SPDX-FileCopyrightText: Intel Corporation
//
// SPDX-License-Identifier: BSD-3-Clause
 
#pragma once
 
#include <iterator>
 
#include <dr/concepts/concepts.hpp>
#include <dr/detail/ranges_shim.hpp>
 
namespace dr {
 
template <std::forward_iterator I>
class remote_subrange : public rng::subrange<I, I> {
  using base = rng::subrange<I, I>;
 
public:
  remote_subrange()
    requires std::default_initializable<I>
  = default;
 
  constexpr remote_subrange(I first, I last, std::size_t rank)
      : base(first, last), rank_(rank) {}
 
  template <rng::forward_range R>
  constexpr remote_subrange(R &&r, std::size_t rank)
      : base(rng::begin(r), rng::end(r)), rank_(rank) {}
 
  template <dr::remote_range R>
  constexpr remote_subrange(R &&r)
      : base(rng::begin(r), rng::end(r)), rank_(dr::ranges::rank(r)) {}
 
  constexpr std::size_t rank() const noexcept { return rank_; }
 
private:
  std::size_t rank_;
};
 
template <rng::forward_range R>
remote_subrange(R &&, std::size_t) -> remote_subrange<rng::iterator_t<R>>;
 
template <dr::remote_range R>
remote_subrange(R &&) -> remote_subrange<rng::iterator_t<R>>;
 
} // namespace dr
 
#if !defined(DR_SPEC)
 
// Needed to satisfy concepts for rng::begin
template <typename R>
inline constexpr bool rng::enable_borrowed_range<dr::remote_subrange<R>> = true;
 
#endif