cpp-lazy-stream/include/stream/count.h

//
//  count.h
//  stream
//
//  Created by Sam Jaffe on 3/30/23.
//

#pragma once

#include <optional>

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

#define FWD(x) std::forward<decltype(x)>(x)

namespace stream::ranges {
template <typename It, typename S, typename Pred,
          typename Proj = detail::identity>
bool any_of(It it, S end, Pred pred, Proj proj = {}) {
  for (; it != end; ++it) {
    if (std::invoke(pred, std::invoke(proj, *it))) { return true; }
  }
  return false;
}

template <typename Stream, typename Pred, typename Proj = detail::identity>
bool any_of(Stream const & stream, Pred pred, Proj proj = {}) {
  return any_of(stream.begin(), stream.end(), std::move(pred), std::move(proj));
}

template <typename It, typename S, typename Pred,
          typename Proj = detail::identity>
bool none_of(It it, S end, Pred pred, Proj proj = {}) {
  return !any_of(it, end, std::move(pred), std::move(proj));
}

template <typename Stream, typename Pred, typename Proj = detail::identity>
bool none_of(Stream const & stream, Pred pred, Proj proj = {}) {
  return none_of(stream.begin(), stream.end(), std::move(pred),
                 std::move(proj));
}

template <typename It, typename S, typename Pred,
          typename Proj = detail::identity>
bool all_of(It it, S end, Pred pred, Proj proj = {}) {
  for (; it != end; ++it) {
    if (!std::invoke(pred, std::invoke(proj, *it))) { return false; }
  }
  return true;
}

template <typename Stream, typename Pred, typename Proj = detail::identity>
bool all_of(Stream const & stream, Pred pred, Proj proj = {}) {
  return all_of(stream.begin(), stream.end(), std::move(pred), std::move(proj));
}

template <typename It, typename S, typename T, typename Proj = detail::identity>
bool count(It it, S end, T const & value, Proj proj = {}) {
  size_t result = 0;
  for (; it != end; ++it) {
    if (value == std::invoke(proj, *it)) { ++result; }
  }
  return result;
}

template <typename Stream, typename T, typename Proj = detail::identity>
bool count(Stream const & stream, T const & value, Proj proj = {}) {
  return count(stream.begin(), stream.end(), value, std::move(proj));
}

template <typename It, typename S, typename Pred,
          typename Proj = detail::identity>
auto count_if(It it, S end, Pred pred, Proj proj = {}) {
  size_t result = 0;
  for (; it != end; ++it) {
    if (std::invoke(pred, std::invoke(proj, *it))) { ++result; }
  }
  return result;
}

template <typename Stream, typename Pred, typename Proj = detail::identity>
auto count_if(Stream const & stream, Pred pred, Proj proj = {}) {
  return count_if(stream.begin(), stream.end(), std::move(pred),
                  std::move(proj));
}
}

#undef FWD