cpp-lazy-stream/include/stream/iterator/transform_iterator.h

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

#pragma once

#include <iterator/proxy.h>

#include <stream/forward.h>

namespace stream::ranges {
template <typename It, typename Proj>
class transform_iterator : public proxy<It, transform_iterator<It, Proj>> {
private:
  using super_t = proxy<It, transform_iterator<It, Proj>>;

private:
  Proj projection_;

public:
  transform_iterator() = default;
  transform_iterator(It iter, Proj projection)
      : super_t(std::move(iter)), projection_(projection) {}

  decltype(auto) dereference() const {
    return projection_(super_t::dereference());
  }

  bool at_end() const { return super_t::impl().at_end(); }
};
}

MAKE_ITERATOR_FACADE_TYPEDEFS_T(stream::ranges::transform_iterator);