cpp-lazy-stream/include/stream/detail/named_pair.h

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

#pragma once

#ifndef CONCAT
#define CONCAT2(A, B) A##B
#define CONCAT(A, B) CONCAT2(A, B)
#endif

#define NAMED_PAIR_CLASS_NAME(first, second)                                   \
  CONCAT(CONCAT(CONCAT(first, _), second), _result)

#define NAMED_PAIR(l, r)                                                       \
  template <typename L, typename R> struct NAMED_PAIR_CLASS_NAME(l, r) {       \
    NAMED_PAIR_CLASS_NAME(l, r)(L l, R r) : l(l), r(r) {}                      \
    L l;                                                                       \
    R r;                                                                       \
  }

namespace stream::detail {
NAMED_PAIR(in, fun);
NAMED_PAIR(min, max);
}