cpp-lazy-stream/include/stream/algorithm/equal.h

//
//  equal.h
//  stream
//
//  Created by Sam Jaffe on 4/2/23.
//

#pragma once

#include <stream/forward.h>

#include <stream/detail/invoke.h>
#include <stream/detail/traits.h>

#include <stream/detail/macro.h>

namespace stream::range {

template <typename It1, typename S1, typename It2, typename S2,
          typename Cmp = std::equal_to<>, typename Proj1 = detail::identity,
          typename Proj2 = detail::identity,
          REQUIRES((detail::is_comparable_v<It1, S1> &&
                    detail::is_comparable_v<It2, S2>))>
bool equal(It1 it1, S1 end1, It2 it2, S2 end2, Cmp cmp = {}, Proj1 proj1 = {},
           Proj2 proj2 = {}) {
  if constexpr (detail::is_sized_sentinel_v<It1, S1> &&
                detail::is_sized_sentinel_v<It2, S2>) {
    if ((end1 - it1) != (end2 - it2)) { return false; }
  }
  for (; it1 != end1 && it2 != end2; ++it1, ++it2) {
    if (!detail::invoke(cmp, *it1, *it2, proj1, proj2)) { return false; }
  }
  return (it1 == end1) && (it2 == end2);
}

template <typename R1, typename R2, typename Cmp = std::equal_to<>,
          typename Proj1 = detail::identity, typename Proj2 = detail::identity>
bool equal(R1 const r1, R2 const & r2, Cmp cmp = {}, Proj1 proj1 = {},
           Proj2 proj2 = {}) {
  return equal(r1.begin(), r1.end(), r2.begin(), r2.end(), std::ref(cmp),
               std::ref(proj1), std::ref(proj2));
}

}

#include <stream/detail/undef.h>