1 /* Error observers for a very simple basic_result type
2 (C) 2017-2022 Niall Douglas <http://www.nedproductions.biz/> (2 commits)
6 Boost Software License - Version 1.0 - August 17th, 2003
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31 #ifndef BOOST_OUTCOME_BASIC_RESULT_ERROR_OBSERVERS_HPP
32 #define BOOST_OUTCOME_BASIC_RESULT_ERROR_OBSERVERS_HPP
34 #include "basic_result_storage.hpp"
36 BOOST_OUTCOME_V2_NAMESPACE_EXPORT_BEGIN
40 template <class Base, class EC, class NoValuePolicy> class basic_result_error_observers : public Base
43 using error_type = EC;
46 constexpr error_type &assume_error() & noexcept
48 NoValuePolicy::narrow_error_check(static_cast<basic_result_error_observers &>(*this));
49 return this->_state._error;
51 constexpr const error_type &assume_error() const &noexcept
53 NoValuePolicy::narrow_error_check(static_cast<const basic_result_error_observers &>(*this));
54 return this->_state._error;
56 constexpr error_type &&assume_error() && noexcept
58 NoValuePolicy::narrow_error_check(static_cast<basic_result_error_observers &&>(*this));
59 return static_cast<error_type &&>(this->_state._error);
61 constexpr const error_type &&assume_error() const &&noexcept
63 NoValuePolicy::narrow_error_check(static_cast<const basic_result_error_observers &&>(*this));
64 return static_cast<const error_type &&>(this->_state._error);
67 constexpr error_type &error() &
69 NoValuePolicy::wide_error_check(static_cast<basic_result_error_observers &>(*this));
70 return this->_state._error;
72 constexpr const error_type &error() const &
74 NoValuePolicy::wide_error_check(static_cast<const basic_result_error_observers &>(*this));
75 return this->_state._error;
77 constexpr error_type &&error() &&
79 NoValuePolicy::wide_error_check(static_cast<basic_result_error_observers &&>(*this));
80 return static_cast<error_type &&>(this->_state._error);
82 constexpr const error_type &&error() const &&
84 NoValuePolicy::wide_error_check(static_cast<const basic_result_error_observers &&>(*this));
85 return static_cast<const error_type &&>(this->_state._error);
88 template <class Base, class NoValuePolicy> class basic_result_error_observers<Base, void, NoValuePolicy> : public Base
92 constexpr void assume_error() const noexcept { NoValuePolicy::narrow_error_check(*this); }
93 constexpr void error() const { NoValuePolicy::wide_error_check(*this); }
96 BOOST_OUTCOME_V2_NAMESPACE_END