/* Error observers for a very simple basic_result type
(C) 2017-2019 Niall Douglas <http://www.nedproductions.biz/> (2 commits)
File Created: Oct 2017


Boost Software License - Version 1.0 - August 17th, 2003

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*/

#ifndef BOOST_OUTCOME_BASIC_RESULT_ERROR_OBSERVERS_HPP
#define BOOST_OUTCOME_BASIC_RESULT_ERROR_OBSERVERS_HPP

#include "basic_result_storage.hpp"

BOOST_OUTCOME_V2_NAMESPACE_EXPORT_BEGIN

namespace detail
{
  template <class Base, class EC, class NoValuePolicy> class basic_result_error_observers : public Base
  {
  public:
    using error_type = EC;
    using Base::Base;

    constexpr error_type &assume_error() & noexcept
    {
      NoValuePolicy::narrow_error_check(static_cast<basic_result_error_observers &>(*this));
      return this->_error;
    }
    constexpr const error_type &assume_error() const &noexcept
    {
      NoValuePolicy::narrow_error_check(static_cast<const basic_result_error_observers &>(*this));
      return this->_error;
    }
    constexpr error_type &&assume_error() && noexcept
    {
      NoValuePolicy::narrow_error_check(static_cast<basic_result_error_observers &&>(*this));
      return static_cast<error_type &&>(this->_error);
    }
    constexpr const error_type &&assume_error() const &&noexcept
    {
      NoValuePolicy::narrow_error_check(static_cast<const basic_result_error_observers &&>(*this));
      return static_cast<const error_type &&>(this->_error);
    }

    constexpr error_type &error() &
    {
      NoValuePolicy::wide_error_check(static_cast<basic_result_error_observers &>(*this));
      return this->_error;
    }
    constexpr const error_type &error() const &
    {
      NoValuePolicy::wide_error_check(static_cast<const basic_result_error_observers &>(*this));
      return this->_error;
    }
    constexpr error_type &&error() &&
    {
      NoValuePolicy::wide_error_check(static_cast<basic_result_error_observers &&>(*this));
      return static_cast<error_type &&>(this->_error);
    }
    constexpr const error_type &&error() const &&
    {
      NoValuePolicy::wide_error_check(static_cast<const basic_result_error_observers &&>(*this));
      return static_cast<const error_type &&>(this->_error);
    }
  };
  template <class Base, class NoValuePolicy> class basic_result_error_observers<Base, void, NoValuePolicy> : public Base
  {
  public:
    using Base::Base;
    constexpr void assume_error() const noexcept { NoValuePolicy::narrow_error_check(*this); }
    constexpr void error() const { NoValuePolicy::wide_error_check(*this); }
  };
}  // namespace detail
BOOST_OUTCOME_V2_NAMESPACE_END

#endif