#ifndef ITER_UNIQUE_EVERSEEN_HPP_

#define ITER_UNIQUE_EVERSEEN_HPP_

#include "internal/iterbase.hpp"

#include "filter.hpp"

#include <type_traits>

#include <functional>

#include <utility>

#include <unordered_set>

#include <iterator>

namespace iter {

template <typename Container>

auto unique_everseen(Container&& container) {

using elem_type = impl::iterator_deref<Container>;

auto func = [elem_seen = std::unordered_set<std::decay_t<elem_type>>()](

const elem_type& e) mutable {

return elem_seen.insert(e).second;

};

return filter(func, std::forward<Container>(container));

}

template <typename T>

auto unique_everseen(std::initializer_list<T> il) {

auto func = [elem_seen = std::unordered_set<T>()](const T& e) mutable {

return elem_seen.insert(e).second;

};

return filter(func, il);

}

}

#endif