| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| //the code refer: https://github.com/TartanLlama/expected/blob/master/include/tl/expected.hpp |
| /// |
| // expected - An implementation of std::expected with extensions |
| // Written in 2017 by Sy Brand (tartanllama@gmail.com, @TartanLlama) |
| // |
| // Documentation available at http://tl.tartanllama.xyz/ |
| // |
| // To the extent possible under law, the author(s) have dedicated all |
| // copyright and related and neighboring rights to this software to the |
| // public domain worldwide. This software is distributed without any warranty. |
| // |
| // You should have received a copy of the CC0 Public Domain Dedication |
| // along with this software. If not, see |
| // <http://creativecommons.org/publicdomain/zero/1.0/>. |
| /// |
| |
| // clang-format off |
| // NOLINTBEGIN |
| #ifndef TL_EXPECTED_HPP |
| #define TL_EXPECTED_HPP |
| |
| #define TL_EXPECTED_VERSION_MAJOR 1 |
| #define TL_EXPECTED_VERSION_MINOR 1 |
| #define TL_EXPECTED_VERSION_PATCH 0 |
| |
| #include <exception> |
| #include <functional> |
| #include <type_traits> |
| #include <utility> |
| |
| #if defined(__EXCEPTIONS) || defined(_CPPUNWIND) |
| #define TL_EXPECTED_EXCEPTIONS_ENABLED |
| #endif |
| |
| #if (defined(_MSC_VER) && _MSC_VER == 1900) |
| #define TL_EXPECTED_MSVC2015 |
| #define TL_EXPECTED_MSVC2015_CONSTEXPR |
| #else |
| #define TL_EXPECTED_MSVC2015_CONSTEXPR constexpr |
| #endif |
| |
| #if (defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ <= 9 && \ |
| !defined(__clang__)) |
| #define TL_EXPECTED_GCC49 |
| #endif |
| |
| #if (defined(__GNUC__) && __GNUC__ == 5 && __GNUC_MINOR__ <= 4 && \ |
| !defined(__clang__)) |
| #define TL_EXPECTED_GCC54 |
| #endif |
| |
| #if (defined(__GNUC__) && __GNUC__ == 5 && __GNUC_MINOR__ <= 5 && \ |
| !defined(__clang__)) |
| #define TL_EXPECTED_GCC55 |
| #endif |
| |
| #if !defined(TL_ASSERT) |
| //can't have assert in constexpr in C++11 and GCC 4.9 has a compiler bug |
| #if (__cplusplus > 201103L) && !defined(TL_EXPECTED_GCC49) |
| #include <cassert> |
| #define TL_ASSERT(x) assert(x) |
| #else |
| #define TL_ASSERT(x) |
| #endif |
| #endif |
| |
| #if (defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ <= 9 && \ |
| !defined(__clang__)) |
| // GCC < 5 doesn't support overloading on const&& for member functions |
| |
| #define TL_EXPECTED_NO_CONSTRR |
| // GCC < 5 doesn't support some standard C++11 type traits |
| #define TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) \ |
| std::has_trivial_copy_constructor<T> |
| #define TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T) \ |
| std::has_trivial_copy_assign<T> |
| |
| // This one will be different for GCC 5.7 if it's ever supported |
| #define TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T) \ |
| std::is_trivially_destructible<T> |
| |
| // GCC 5 < v < 8 has a bug in is_trivially_copy_constructible which breaks |
| // std::vector for non-copyable types |
| #elif (defined(__GNUC__) && __GNUC__ < 8 && !defined(__clang__)) |
| #ifndef TL_GCC_LESS_8_TRIVIALLY_COPY_CONSTRUCTIBLE_MUTEX |
| #define TL_GCC_LESS_8_TRIVIALLY_COPY_CONSTRUCTIBLE_MUTEX |
| namespace tl { |
| namespace detail { |
| template <class T> |
| struct is_trivially_copy_constructible |
| : std::is_trivially_copy_constructible<T> {}; |
| #ifdef _GLIBCXX_VECTOR |
| template <class T, class A> |
| struct is_trivially_copy_constructible<std::vector<T, A>> : std::false_type {}; |
| #endif |
| } // namespace detail |
| } // namespace tl |
| #endif |
| |
| #define TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) \ |
| tl::detail::is_trivially_copy_constructible<T> |
| #define TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T) \ |
| std::is_trivially_copy_assignable<T> |
| #define TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T) \ |
| std::is_trivially_destructible<T> |
| #else |
| #define TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) \ |
| std::is_trivially_copy_constructible<T> |
| #define TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T) \ |
| std::is_trivially_copy_assignable<T> |
| #define TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T) \ |
| std::is_trivially_destructible<T> |
| #endif |
| |
| #if __cplusplus > 201103L |
| #define TL_EXPECTED_CXX14 |
| #endif |
| |
| #ifdef TL_EXPECTED_GCC49 |
| #define TL_EXPECTED_GCC49_CONSTEXPR |
| #else |
| #define TL_EXPECTED_GCC49_CONSTEXPR constexpr |
| #endif |
| |
| #if (__cplusplus == 201103L || defined(TL_EXPECTED_MSVC2015) || \ |
| defined(TL_EXPECTED_GCC49)) |
| #define TL_EXPECTED_11_CONSTEXPR |
| #else |
| #define TL_EXPECTED_11_CONSTEXPR constexpr |
| #endif |
| |
| namespace tl { |
| template <class T, class E> class expected; |
| |
| #ifndef TL_MONOSTATE_INPLACE_MUTEX |
| #define TL_MONOSTATE_INPLACE_MUTEX |
| class monostate {}; |
| |
| struct in_place_t { |
| explicit in_place_t() = default; |
| }; |
| static constexpr in_place_t in_place{}; |
| #endif |
| |
| template <class E> class unexpected { |
| public: |
| static_assert(!std::is_same<E, void>::value, "E must not be void"); |
| |
| unexpected() = delete; |
| constexpr explicit unexpected(const E &e) : m_val(e) {} |
| |
| constexpr explicit unexpected(E &&e) : m_val(std::move(e)) {} |
| |
| template <class... Args, typename std::enable_if<std::is_constructible< |
| E, Args &&...>::value>::type * = nullptr> |
| constexpr explicit unexpected(Args &&...args) |
| : m_val(std::forward<Args>(args)...) {} |
| template < |
| class U, class... Args, |
| typename std::enable_if<std::is_constructible< |
| E, std::initializer_list<U> &, Args &&...>::value>::type * = nullptr> |
| constexpr explicit unexpected(std::initializer_list<U> l, Args &&...args) |
| : m_val(l, std::forward<Args>(args)...) {} |
| |
| constexpr const E &value() const & { return m_val; } |
| TL_EXPECTED_11_CONSTEXPR E &value() & { return m_val; } |
| TL_EXPECTED_11_CONSTEXPR E &&value() && { return std::move(m_val); } |
| constexpr const E &&value() const && { return std::move(m_val); } |
| |
| private: |
| E m_val; |
| }; |
| |
| #ifdef __cpp_deduction_guides |
| template <class E> unexpected(E) -> unexpected<E>; |
| #endif |
| |
| template <class E> |
| constexpr bool operator==(const unexpected<E> &lhs, const unexpected<E> &rhs) { |
| return lhs.value() == rhs.value(); |
| } |
| template <class E> |
| constexpr auto operator<=>(const unexpected<E> &lhs, const unexpected<E> &rhs) { |
| return lhs.value() <=> rhs.value(); |
| } |
| |
| template <class E> |
| unexpected<typename std::decay<E>::type> make_unexpected(E &&e) { |
| return unexpected<typename std::decay<E>::type>(std::forward<E>(e)); |
| } |
| |
| struct unexpect_t { |
| unexpect_t() = default; |
| }; |
| static constexpr unexpect_t unexpect{}; |
| |
| namespace detail { |
| template <typename E> |
| [[noreturn]] TL_EXPECTED_11_CONSTEXPR void throw_exception(E &&e) { |
| #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED |
| throw std::forward<E>(e); |
| #else |
| (void)e; |
| #ifdef _MSC_VER |
| __assume(0); |
| #else |
| LOG(FATAL) << "__builtin_unreachable"; |
| __builtin_unreachable(); |
| #endif |
| #endif |
| } |
| |
| #ifndef TL_TRAITS_MUTEX |
| #define TL_TRAITS_MUTEX |
| // C++14-style aliases for brevity |
| template <class T> using remove_const_t = typename std::remove_const<T>::type; |
| template <class T> |
| using remove_reference_t = typename std::remove_reference<T>::type; |
| template <class T> using decay_t = typename std::decay<T>::type; |
| template <bool E, class T = void> |
| using enable_if_t = typename std::enable_if<E, T>::type; |
| template <bool B, class T, class F> |
| using conditional_t = typename std::conditional<B, T, F>::type; |
| |
| // std::conjunction from C++17 |
| template <class...> struct conjunction : std::true_type {}; |
| template <class B> struct conjunction<B> : B {}; |
| template <class B, class... Bs> |
| struct conjunction<B, Bs...> |
| : std::conditional<bool(B::value), conjunction<Bs...>, B>::type {}; |
| |
| #if defined(_LIBCPP_VERSION) && __cplusplus == 201103L |
| #define TL_TRAITS_LIBCXX_MEM_FN_WORKAROUND |
| #endif |
| |
| // In C++11 mode, there's an issue in libc++'s std::mem_fn |
| // which results in a hard-error when using it in a noexcept expression |
| // in some cases. This is a check to workaround the common failing case. |
| #ifdef TL_TRAITS_LIBCXX_MEM_FN_WORKAROUND |
| template <class T> |
| struct is_pointer_to_non_const_member_func : std::false_type {}; |
| template <class T, class Ret, class... Args> |
| struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...)> |
| : std::true_type {}; |
| template <class T, class Ret, class... Args> |
| struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...) &> |
| : std::true_type {}; |
| template <class T, class Ret, class... Args> |
| struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...) &&> |
| : std::true_type {}; |
| template <class T, class Ret, class... Args> |
| struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...) volatile> |
| : std::true_type {}; |
| template <class T, class Ret, class... Args> |
| struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...) volatile &> |
| : std::true_type {}; |
| template <class T, class Ret, class... Args> |
| struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...) volatile &&> |
| : std::true_type {}; |
| |
| template <class T> struct is_const_or_const_ref : std::false_type {}; |
| template <class T> struct is_const_or_const_ref<T const &> : std::true_type {}; |
| template <class T> struct is_const_or_const_ref<T const> : std::true_type {}; |
| #endif |
| |
| // std::invoke from C++17 |
| // https://stackoverflow.com/questions/38288042/c11-14-invoke-workaround |
| template < |
| typename Fn, typename... Args, |
| #ifdef TL_TRAITS_LIBCXX_MEM_FN_WORKAROUND |
| typename = enable_if_t<!(is_pointer_to_non_const_member_func<Fn>::value && |
| is_const_or_const_ref<Args...>::value)>, |
| #endif |
| typename = enable_if_t<std::is_member_pointer<decay_t<Fn>>::value>, int = 0> |
| constexpr auto invoke(Fn &&f, Args &&...args) noexcept( |
| noexcept(std::mem_fn(f)(std::forward<Args>(args)...))) |
| -> decltype(std::mem_fn(f)(std::forward<Args>(args)...)) { |
| return std::mem_fn(f)(std::forward<Args>(args)...); |
| } |
| |
| template <typename Fn, typename... Args, |
| typename = enable_if_t<!std::is_member_pointer<decay_t<Fn>>::value>> |
| constexpr auto invoke(Fn &&f, Args &&...args) noexcept( |
| noexcept(std::forward<Fn>(f)(std::forward<Args>(args)...))) |
| -> decltype(std::forward<Fn>(f)(std::forward<Args>(args)...)) { |
| return std::forward<Fn>(f)(std::forward<Args>(args)...); |
| } |
| |
| // std::invoke_result from C++17 |
| template <class F, class, class... Us> struct invoke_result_impl; |
| |
| template <class F, class... Us> |
| struct invoke_result_impl< |
| F, |
| decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...), void()), |
| Us...> { |
| using type = |
| decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...)); |
| }; |
| |
| template <class F, class... Us> |
| using invoke_result = invoke_result_impl<F, void, Us...>; |
| |
| template <class F, class... Us> |
| using invoke_result_t = typename invoke_result<F, Us...>::type; |
| |
| #if defined(_MSC_VER) && _MSC_VER <= 1900 |
| // TODO make a version which works with MSVC 2015 |
| template <class T, class U = T> struct is_swappable : std::true_type {}; |
| |
| template <class T, class U = T> struct is_nothrow_swappable : std::true_type {}; |
| #else |
| // https://stackoverflow.com/questions/26744589/what-is-a-proper-way-to-implement-is-swappable-to-test-for-the-swappable-concept |
| namespace swap_adl_tests { |
| // if swap ADL finds this then it would call std::swap otherwise (same |
| // signature) |
| struct tag {}; |
| |
| template <class T> tag swap(T &, T &); |
| template <class T, std::size_t N> tag swap(T (&a)[N], T (&b)[N]); |
| |
| // helper functions to test if an unqualified swap is possible, and if it |
| // becomes std::swap |
| template <class, class> std::false_type can_swap(...) noexcept(false); |
| template <class T, class U, |
| class = decltype(swap(std::declval<T &>(), std::declval<U &>()))> |
| std::true_type can_swap(int) noexcept(noexcept(swap(std::declval<T &>(), |
| std::declval<U &>()))); |
| |
| template <class, class> std::false_type uses_std(...); |
| template <class T, class U> |
| std::is_same<decltype(swap(std::declval<T &>(), std::declval<U &>())), tag> |
| uses_std(int); |
| |
| template <class T> |
| struct is_std_swap_noexcept |
| : std::integral_constant<bool, |
| std::is_nothrow_move_constructible<T>::value && |
| std::is_nothrow_move_assignable<T>::value> {}; |
| |
| template <class T, std::size_t N> |
| struct is_std_swap_noexcept<T[N]> : is_std_swap_noexcept<T> {}; |
| |
| template <class T, class U> |
| struct is_adl_swap_noexcept |
| : std::integral_constant<bool, noexcept(can_swap<T, U>(0))> {}; |
| } // namespace swap_adl_tests |
| |
| template <class T, class U = T> |
| struct is_swappable |
| : std::integral_constant< |
| bool, |
| decltype(detail::swap_adl_tests::can_swap<T, U>(0))::value && |
| (!decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value || |
| (std::is_move_assignable<T>::value && |
| std::is_move_constructible<T>::value))> {}; |
| |
| template <class T, std::size_t N> |
| struct is_swappable<T[N], T[N]> |
| : std::integral_constant< |
| bool, |
| decltype(detail::swap_adl_tests::can_swap<T[N], T[N]>(0))::value && |
| (!decltype(detail::swap_adl_tests::uses_std<T[N], T[N]>( |
| 0))::value || |
| is_swappable<T, T>::value)> {}; |
| |
| template <class T, class U = T> |
| struct is_nothrow_swappable |
| : std::integral_constant< |
| bool, |
| is_swappable<T, U>::value && |
| ((decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value && |
| detail::swap_adl_tests::is_std_swap_noexcept<T>::value) || |
| (!decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value && |
| detail::swap_adl_tests::is_adl_swap_noexcept<T, U>::value))> {}; |
| #endif |
| #endif |
| |
| // Trait for checking if a type is a tl::expected |
| template <class T> struct is_expected_impl : std::false_type {}; |
| template <class T, class E> |
| struct is_expected_impl<expected<T, E>> : std::true_type {}; |
| template <class T> using is_expected = is_expected_impl<decay_t<T>>; |
| |
| template <class T, class E, class U> |
| using expected_enable_forward_value = detail::enable_if_t< |
| std::is_constructible<T, U &&>::value && |
| !std::is_same<detail::decay_t<U>, in_place_t>::value && |
| !std::is_same<expected<T, E>, detail::decay_t<U>>::value && |
| !std::is_same<unexpected<E>, detail::decay_t<U>>::value>; |
| |
| template <class T, class E, class U, class G, class UR, class GR> |
| using expected_enable_from_other = detail::enable_if_t< |
| std::is_constructible<T, UR>::value && |
| std::is_constructible<E, GR>::value && |
| !std::is_constructible<T, expected<U, G> &>::value && |
| !std::is_constructible<T, expected<U, G> &&>::value && |
| !std::is_constructible<T, const expected<U, G> &>::value && |
| !std::is_constructible<T, const expected<U, G> &&>::value && |
| !std::is_convertible<expected<U, G> &, T>::value && |
| !std::is_convertible<expected<U, G> &&, T>::value && |
| !std::is_convertible<const expected<U, G> &, T>::value && |
| !std::is_convertible<const expected<U, G> &&, T>::value>; |
| |
| template <class T, class U> |
| using is_void_or = conditional_t<std::is_void<T>::value, std::true_type, U>; |
| |
| template <class T> |
| using is_copy_constructible_or_void = |
| is_void_or<T, std::is_copy_constructible<T>>; |
| |
| template <class T> |
| using is_move_constructible_or_void = |
| is_void_or<T, std::is_move_constructible<T>>; |
| |
| template <class T> |
| using is_copy_assignable_or_void = is_void_or<T, std::is_copy_assignable<T>>; |
| |
| template <class T> |
| using is_move_assignable_or_void = is_void_or<T, std::is_move_assignable<T>>; |
| |
| } // namespace detail |
| |
| namespace detail { |
| struct no_init_t {}; |
| static constexpr no_init_t no_init{}; |
| |
| // Implements the storage of the values, and ensures that the destructor is |
| // trivial if it can be. |
| // |
| // This specialization is for where neither `T` or `E` is trivially |
| // destructible, so the destructors must be called on destruction of the |
| // `expected` |
| template <class T, class E, bool = std::is_trivially_destructible<T>::value, |
| bool = std::is_trivially_destructible<E>::value> |
| struct expected_storage_base { |
| constexpr expected_storage_base() : m_val(T{}), m_has_val(true) {} |
| constexpr expected_storage_base(no_init_t) : m_no_init(), m_has_val(false) {} |
| |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * = |
| nullptr> |
| constexpr expected_storage_base(in_place_t, Args &&...args) |
| : m_val(std::forward<Args>(args)...), m_has_val(true) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| T, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr expected_storage_base(in_place_t, std::initializer_list<U> il, |
| Args &&...args) |
| : m_val(il, std::forward<Args>(args)...), m_has_val(true) {} |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * = |
| nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, Args &&...args) |
| : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| E, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, |
| std::initializer_list<U> il, |
| Args &&...args) |
| : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {} |
| |
| ~expected_storage_base() { |
| if (m_has_val) { |
| m_val.~T(); |
| } else { |
| m_unexpect.~unexpected<E>(); |
| } |
| } |
| union { |
| T m_val; |
| unexpected<E> m_unexpect; |
| char m_no_init; |
| }; |
| bool m_has_val; |
| }; |
| |
| // This specialization is for when both `T` and `E` are trivially-destructible, |
| // so the destructor of the `expected` can be trivial. |
| template <class T, class E> struct expected_storage_base<T, E, true, true> { |
| constexpr expected_storage_base() : m_val(T{}), m_has_val(true) {} |
| constexpr expected_storage_base(no_init_t) : m_no_init(), m_has_val(false) {} |
| |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * = |
| nullptr> |
| constexpr expected_storage_base(in_place_t, Args &&...args) |
| : m_val(std::forward<Args>(args)...), m_has_val(true) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| T, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr expected_storage_base(in_place_t, std::initializer_list<U> il, |
| Args &&...args) |
| : m_val(il, std::forward<Args>(args)...), m_has_val(true) {} |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * = |
| nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, Args &&...args) |
| : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| E, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, |
| std::initializer_list<U> il, |
| Args &&...args) |
| : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {} |
| |
| ~expected_storage_base() = default; |
| union { |
| T m_val; |
| unexpected<E> m_unexpect; |
| char m_no_init; |
| }; |
| bool m_has_val; |
| }; |
| |
| // T is trivial, E is not. |
| template <class T, class E> struct expected_storage_base<T, E, true, false> { |
| constexpr expected_storage_base() : m_val(T{}), m_has_val(true) {} |
| TL_EXPECTED_MSVC2015_CONSTEXPR expected_storage_base(no_init_t) |
| : m_no_init(), m_has_val(false) {} |
| |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * = |
| nullptr> |
| constexpr expected_storage_base(in_place_t, Args &&...args) |
| : m_val(std::forward<Args>(args)...), m_has_val(true) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| T, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr expected_storage_base(in_place_t, std::initializer_list<U> il, |
| Args &&...args) |
| : m_val(il, std::forward<Args>(args)...), m_has_val(true) {} |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * = |
| nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, Args &&...args) |
| : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| E, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, |
| std::initializer_list<U> il, |
| Args &&...args) |
| : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {} |
| |
| ~expected_storage_base() { |
| if (!m_has_val) { |
| m_unexpect.~unexpected<E>(); |
| } |
| } |
| |
| union { |
| T m_val; |
| unexpected<E> m_unexpect; |
| char m_no_init; |
| }; |
| bool m_has_val; |
| }; |
| |
| // E is trivial, T is not. |
| template <class T, class E> struct expected_storage_base<T, E, false, true> { |
| constexpr expected_storage_base() : m_val(T{}), m_has_val(true) {} |
| constexpr expected_storage_base(no_init_t) : m_no_init(), m_has_val(false) {} |
| |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * = |
| nullptr> |
| constexpr expected_storage_base(in_place_t, Args &&...args) |
| : m_val(std::forward<Args>(args)...), m_has_val(true) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| T, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr expected_storage_base(in_place_t, std::initializer_list<U> il, |
| Args &&...args) |
| : m_val(il, std::forward<Args>(args)...), m_has_val(true) {} |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * = |
| nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, Args &&...args) |
| : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| E, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, |
| std::initializer_list<U> il, |
| Args &&...args) |
| : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {} |
| |
| ~expected_storage_base() { |
| if (m_has_val) { |
| m_val.~T(); |
| } |
| } |
| union { |
| T m_val; |
| unexpected<E> m_unexpect; |
| char m_no_init; |
| }; |
| bool m_has_val; |
| }; |
| |
| // `T` is `void`, `E` is trivially-destructible |
| template <class E> struct expected_storage_base<void, E, false, true> { |
| #if __GNUC__ <= 5 |
| //no constexpr for GCC 4/5 bug |
| #else |
| TL_EXPECTED_MSVC2015_CONSTEXPR |
| #endif |
| expected_storage_base() : m_has_val(true) {} |
| |
| constexpr expected_storage_base(no_init_t) : m_val(), m_has_val(false) {} |
| |
| constexpr expected_storage_base(in_place_t) : m_has_val(true) {} |
| |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * = |
| nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, Args &&...args) |
| : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| E, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, |
| std::initializer_list<U> il, |
| Args &&...args) |
| : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {} |
| |
| ~expected_storage_base() = default; |
| struct dummy {}; |
| union { |
| unexpected<E> m_unexpect; |
| dummy m_val; |
| }; |
| bool m_has_val; |
| }; |
| |
| // `T` is `void`, `E` is not trivially-destructible |
| template <class E> struct expected_storage_base<void, E, false, false> { |
| constexpr expected_storage_base() : m_dummy(), m_has_val(true) {} |
| constexpr expected_storage_base(no_init_t) : m_dummy(), m_has_val(false) {} |
| |
| constexpr expected_storage_base(in_place_t) : m_dummy(), m_has_val(true) {} |
| |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * = |
| nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, Args &&...args) |
| : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| E, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr explicit expected_storage_base(unexpect_t, |
| std::initializer_list<U> il, |
| Args &&...args) |
| : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {} |
| |
| ~expected_storage_base() { |
| if (!m_has_val) { |
| m_unexpect.~unexpected<E>(); |
| } |
| } |
| |
| union { |
| unexpected<E> m_unexpect; |
| char m_dummy; |
| }; |
| bool m_has_val; |
| }; |
| |
| // This base class provides some handy member functions which can be used in |
| // further derived classes |
| template <class T, class E> |
| struct expected_operations_base : expected_storage_base<T, E> { |
| using expected_storage_base<T, E>::expected_storage_base; |
| |
| template <class... Args> void construct(Args &&...args) noexcept { |
| new (std::addressof(this->m_val)) T(std::forward<Args>(args)...); |
| this->m_has_val = true; |
| } |
| |
| template <class Rhs> void construct_with(Rhs &&rhs) noexcept { |
| new (std::addressof(this->m_val)) T(std::forward<Rhs>(rhs).get()); |
| this->m_has_val = true; |
| } |
| |
| template <class... Args> void construct_error(Args &&...args) noexcept { |
| new (std::addressof(this->m_unexpect)) |
| unexpected<E>(std::forward<Args>(args)...); |
| this->m_has_val = false; |
| } |
| |
| #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED |
| |
| // These assign overloads ensure that the most efficient assignment |
| // implementation is used while maintaining the strong exception guarantee. |
| // The problematic case is where rhs has a value, but *this does not. |
| // |
| // This overload handles the case where we can just copy-construct `T` |
| // directly into place without throwing. |
| template <class U = T, |
| detail::enable_if_t<std::is_nothrow_copy_constructible<U>::value> |
| * = nullptr> |
| void assign(const expected_operations_base &rhs) noexcept { |
| if (!this->m_has_val && rhs.m_has_val) { |
| geterr().~unexpected<E>(); |
| construct(rhs.get()); |
| } else { |
| assign_common(rhs); |
| } |
| } |
| |
| // This overload handles the case where we can attempt to create a copy of |
| // `T`, then no-throw move it into place if the copy was successful. |
| template <class U = T, |
| detail::enable_if_t<!std::is_nothrow_copy_constructible<U>::value && |
| std::is_nothrow_move_constructible<U>::value> |
| * = nullptr> |
| void assign(const expected_operations_base &rhs) noexcept { |
| if (!this->m_has_val && rhs.m_has_val) { |
| T tmp = rhs.get(); |
| geterr().~unexpected<E>(); |
| construct(std::move(tmp)); |
| } else { |
| assign_common(rhs); |
| } |
| } |
| |
| // This overload is the worst-case, where we have to move-construct the |
| // unexpected value into temporary storage, then try to copy the T into place. |
| // If the construction succeeds, then everything is fine, but if it throws, |
| // then we move the old unexpected value back into place before rethrowing the |
| // exception. |
| template <class U = T, |
| detail::enable_if_t<!std::is_nothrow_copy_constructible<U>::value && |
| !std::is_nothrow_move_constructible<U>::value> |
| * = nullptr> |
| void assign(const expected_operations_base &rhs) { |
| if (!this->m_has_val && rhs.m_has_val) { |
| auto tmp = std::move(geterr()); |
| geterr().~unexpected<E>(); |
| |
| #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED |
| try { |
| construct(rhs.get()); |
| } catch (...) { |
| geterr() = std::move(tmp); |
| throw; |
| } |
| #else |
| construct(rhs.get()); |
| #endif |
| } else { |
| assign_common(rhs); |
| } |
| } |
| |
| // These overloads do the same as above, but for rvalues |
| template <class U = T, |
| detail::enable_if_t<std::is_nothrow_move_constructible<U>::value> |
| * = nullptr> |
| void assign(expected_operations_base &&rhs) noexcept { |
| if (!this->m_has_val && rhs.m_has_val) { |
| geterr().~unexpected<E>(); |
| construct(std::move(rhs).get()); |
| } else { |
| assign_common(std::move(rhs)); |
| } |
| } |
| |
| template <class U = T, |
| detail::enable_if_t<!std::is_nothrow_move_constructible<U>::value> |
| * = nullptr> |
| void assign(expected_operations_base &&rhs) { |
| if (!this->m_has_val && rhs.m_has_val) { |
| auto tmp = std::move(geterr()); |
| geterr().~unexpected<E>(); |
| #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED |
| try { |
| construct(std::move(rhs).get()); |
| } catch (...) { |
| geterr() = std::move(tmp); |
| throw; |
| } |
| #else |
| construct(std::move(rhs).get()); |
| #endif |
| } else { |
| assign_common(std::move(rhs)); |
| } |
| } |
| |
| #else |
| |
| // If exceptions are disabled then we can just copy-construct |
| void assign(const expected_operations_base &rhs) noexcept { |
| if (!this->m_has_val && rhs.m_has_val) { |
| geterr().~unexpected<E>(); |
| construct(rhs.get()); |
| } else { |
| assign_common(rhs); |
| } |
| } |
| |
| void assign(expected_operations_base &&rhs) noexcept { |
| if (!this->m_has_val && rhs.m_has_val) { |
| geterr().~unexpected<E>(); |
| construct(std::move(rhs).get()); |
| } else { |
| assign_common(std::move(rhs)); |
| } |
| } |
| |
| #endif |
| |
| // The common part of move/copy assigning |
| template <class Rhs> void assign_common(Rhs &&rhs) { |
| if (this->m_has_val) { |
| if (rhs.m_has_val) { |
| get() = std::forward<Rhs>(rhs).get(); |
| } else { |
| destroy_val(); |
| construct_error(std::forward<Rhs>(rhs).geterr()); |
| } |
| } else { |
| if (!rhs.m_has_val) { |
| geterr() = std::forward<Rhs>(rhs).geterr(); |
| } |
| } |
| } |
| |
| bool has_value() const { return this->m_has_val; } |
| |
| TL_EXPECTED_11_CONSTEXPR T &get() & { return this->m_val; } |
| constexpr const T &get() const & { return this->m_val; } |
| TL_EXPECTED_11_CONSTEXPR T &&get() && { return std::move(this->m_val); } |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| constexpr const T &&get() const && { return std::move(this->m_val); } |
| #endif |
| |
| TL_EXPECTED_11_CONSTEXPR unexpected<E> &geterr() & { |
| return this->m_unexpect; |
| } |
| constexpr const unexpected<E> &geterr() const & { return this->m_unexpect; } |
| TL_EXPECTED_11_CONSTEXPR unexpected<E> &&geterr() && { |
| return std::move(this->m_unexpect); |
| } |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| constexpr const unexpected<E> &&geterr() const && { |
| return std::move(this->m_unexpect); |
| } |
| #endif |
| |
| TL_EXPECTED_11_CONSTEXPR void destroy_val() { get().~T(); } |
| }; |
| |
| // This base class provides some handy member functions which can be used in |
| // further derived classes |
| template <class E> |
| struct expected_operations_base<void, E> : expected_storage_base<void, E> { |
| using expected_storage_base<void, E>::expected_storage_base; |
| |
| template <class... Args> void construct() noexcept { this->m_has_val = true; } |
| |
| // This function doesn't use its argument, but needs it so that code in |
| // levels above this can work independently of whether T is void |
| template <class Rhs> void construct_with(Rhs &&) noexcept { |
| this->m_has_val = true; |
| } |
| |
| template <class... Args> void construct_error(Args &&...args) noexcept { |
| new (std::addressof(this->m_unexpect)) |
| unexpected<E>(std::forward<Args>(args)...); |
| this->m_has_val = false; |
| } |
| |
| template <class Rhs> void assign(Rhs &&rhs) noexcept { |
| if (!this->m_has_val) { |
| if (rhs.m_has_val) { |
| geterr().~unexpected<E>(); |
| construct(); |
| } else { |
| geterr() = std::forward<Rhs>(rhs).geterr(); |
| } |
| } else { |
| if (!rhs.m_has_val) { |
| construct_error(std::forward<Rhs>(rhs).geterr()); |
| } |
| } |
| } |
| |
| bool has_value() const { return this->m_has_val; } |
| |
| TL_EXPECTED_11_CONSTEXPR unexpected<E> &geterr() & { |
| return this->m_unexpect; |
| } |
| constexpr const unexpected<E> &geterr() const & { return this->m_unexpect; } |
| TL_EXPECTED_11_CONSTEXPR unexpected<E> &&geterr() && { |
| return std::move(this->m_unexpect); |
| } |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| constexpr const unexpected<E> &&geterr() const && { |
| return std::move(this->m_unexpect); |
| } |
| #endif |
| |
| TL_EXPECTED_11_CONSTEXPR void destroy_val() { |
| // no-op |
| } |
| }; |
| |
| // This class manages conditionally having a trivial copy constructor |
| // This specialization is for when T and E are trivially copy constructible |
| template <class T, class E, |
| bool = is_void_or<T, TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)>:: |
| value &&TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(E)::value> |
| struct expected_copy_base : expected_operations_base<T, E> { |
| using expected_operations_base<T, E>::expected_operations_base; |
| }; |
| |
| // This specialization is for when T or E are not trivially copy constructible |
| template <class T, class E> |
| struct expected_copy_base<T, E, false> : expected_operations_base<T, E> { |
| using expected_operations_base<T, E>::expected_operations_base; |
| |
| expected_copy_base() = default; |
| expected_copy_base(const expected_copy_base &rhs) |
| : expected_operations_base<T, E>(no_init) { |
| if (rhs.has_value()) { |
| this->construct_with(rhs); |
| } else { |
| this->construct_error(rhs.geterr()); |
| } |
| } |
| |
| expected_copy_base(expected_copy_base &&rhs) = default; |
| expected_copy_base &operator=(const expected_copy_base &rhs) = default; |
| expected_copy_base &operator=(expected_copy_base &&rhs) = default; |
| }; |
| |
| // This class manages conditionally having a trivial move constructor |
| // Unfortunately there's no way to achieve this in GCC < 5 AFAIK, since it |
| // doesn't implement an analogue to std::is_trivially_move_constructible. We |
| // have to make do with a non-trivial move constructor even if T is trivially |
| // move constructible |
| #ifndef TL_EXPECTED_GCC49 |
| template <class T, class E, |
| bool = is_void_or<T, std::is_trivially_move_constructible<T>>::value |
| &&std::is_trivially_move_constructible<E>::value> |
| struct expected_move_base : expected_copy_base<T, E> { |
| using expected_copy_base<T, E>::expected_copy_base; |
| }; |
| #else |
| template <class T, class E, bool = false> struct expected_move_base; |
| #endif |
| template <class T, class E> |
| struct expected_move_base<T, E, false> : expected_copy_base<T, E> { |
| using expected_copy_base<T, E>::expected_copy_base; |
| |
| expected_move_base() = default; |
| expected_move_base(const expected_move_base &rhs) = default; |
| |
| expected_move_base(expected_move_base &&rhs) noexcept( |
| std::is_nothrow_move_constructible<T>::value) |
| : expected_copy_base<T, E>(no_init) { |
| if (rhs.has_value()) { |
| this->construct_with(std::move(rhs)); |
| } else { |
| this->construct_error(std::move(rhs.geterr())); |
| } |
| } |
| expected_move_base &operator=(const expected_move_base &rhs) = default; |
| expected_move_base &operator=(expected_move_base &&rhs) = default; |
| }; |
| |
| // This class manages conditionally having a trivial copy assignment operator |
| template <class T, class E, |
| bool = is_void_or< |
| T, conjunction<TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T), |
| TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T), |
| TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T)>>::value |
| &&TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(E)::value |
| &&TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(E)::value |
| &&TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(E)::value> |
| struct expected_copy_assign_base : expected_move_base<T, E> { |
| using expected_move_base<T, E>::expected_move_base; |
| }; |
| |
| template <class T, class E> |
| struct expected_copy_assign_base<T, E, false> : expected_move_base<T, E> { |
| using expected_move_base<T, E>::expected_move_base; |
| |
| expected_copy_assign_base() = default; |
| expected_copy_assign_base(const expected_copy_assign_base &rhs) = default; |
| |
| expected_copy_assign_base(expected_copy_assign_base &&rhs) = default; |
| expected_copy_assign_base &operator=(const expected_copy_assign_base &rhs) { |
| this->assign(rhs); |
| return *this; |
| } |
| expected_copy_assign_base & |
| operator=(expected_copy_assign_base &&rhs) = default; |
| }; |
| |
| // This class manages conditionally having a trivial move assignment operator |
| // Unfortunately there's no way to achieve this in GCC < 5 AFAIK, since it |
| // doesn't implement an analogue to std::is_trivially_move_assignable. We have |
| // to make do with a non-trivial move assignment operator even if T is trivially |
| // move assignable |
| #ifndef TL_EXPECTED_GCC49 |
| template <class T, class E, |
| bool = |
| is_void_or<T, conjunction<std::is_trivially_destructible<T>, |
| std::is_trivially_move_constructible<T>, |
| std::is_trivially_move_assignable<T>>>:: |
| value &&std::is_trivially_destructible<E>::value |
| &&std::is_trivially_move_constructible<E>::value |
| &&std::is_trivially_move_assignable<E>::value> |
| struct expected_move_assign_base : expected_copy_assign_base<T, E> { |
| using expected_copy_assign_base<T, E>::expected_copy_assign_base; |
| }; |
| #else |
| template <class T, class E, bool = false> struct expected_move_assign_base; |
| #endif |
| |
| template <class T, class E> |
| struct expected_move_assign_base<T, E, false> |
| : expected_copy_assign_base<T, E> { |
| using expected_copy_assign_base<T, E>::expected_copy_assign_base; |
| |
| expected_move_assign_base() = default; |
| expected_move_assign_base(const expected_move_assign_base &rhs) = default; |
| |
| expected_move_assign_base(expected_move_assign_base &&rhs) = default; |
| |
| expected_move_assign_base & |
| operator=(const expected_move_assign_base &rhs) = default; |
| |
| expected_move_assign_base & |
| operator=(expected_move_assign_base &&rhs) noexcept( |
| std::is_nothrow_move_constructible<T>::value |
| &&std::is_nothrow_move_assignable<T>::value) { |
| this->assign(std::move(rhs)); |
| return *this; |
| } |
| }; |
| |
| // expected_delete_ctor_base will conditionally delete copy and move |
| // constructors depending on whether T is copy/move constructible |
| template <class T, class E, |
| bool EnableCopy = (is_copy_constructible_or_void<T>::value && |
| std::is_copy_constructible<E>::value), |
| bool EnableMove = (is_move_constructible_or_void<T>::value && |
| std::is_move_constructible<E>::value)> |
| struct expected_delete_ctor_base { |
| expected_delete_ctor_base() = default; |
| expected_delete_ctor_base(const expected_delete_ctor_base &) = default; |
| expected_delete_ctor_base(expected_delete_ctor_base &&) noexcept = default; |
| expected_delete_ctor_base & |
| operator=(const expected_delete_ctor_base &) = default; |
| expected_delete_ctor_base & |
| operator=(expected_delete_ctor_base &&) noexcept = default; |
| }; |
| |
| template <class T, class E> |
| struct expected_delete_ctor_base<T, E, true, false> { |
| expected_delete_ctor_base() = default; |
| expected_delete_ctor_base(const expected_delete_ctor_base &) = default; |
| expected_delete_ctor_base(expected_delete_ctor_base &&) noexcept = delete; |
| expected_delete_ctor_base & |
| operator=(const expected_delete_ctor_base &) = default; |
| expected_delete_ctor_base & |
| operator=(expected_delete_ctor_base &&) noexcept = default; |
| }; |
| |
| template <class T, class E> |
| struct expected_delete_ctor_base<T, E, false, true> { |
| expected_delete_ctor_base() = default; |
| expected_delete_ctor_base(const expected_delete_ctor_base &) = delete; |
| expected_delete_ctor_base(expected_delete_ctor_base &&) noexcept = default; |
| expected_delete_ctor_base & |
| operator=(const expected_delete_ctor_base &) = default; |
| expected_delete_ctor_base & |
| operator=(expected_delete_ctor_base &&) noexcept = default; |
| }; |
| |
| template <class T, class E> |
| struct expected_delete_ctor_base<T, E, false, false> { |
| expected_delete_ctor_base() = default; |
| expected_delete_ctor_base(const expected_delete_ctor_base &) = delete; |
| expected_delete_ctor_base(expected_delete_ctor_base &&) noexcept = delete; |
| expected_delete_ctor_base & |
| operator=(const expected_delete_ctor_base &) = default; |
| expected_delete_ctor_base & |
| operator=(expected_delete_ctor_base &&) noexcept = default; |
| }; |
| |
| // expected_delete_assign_base will conditionally delete copy and move |
| // constructors depending on whether T and E are copy/move constructible + |
| // assignable |
| template <class T, class E, |
| bool EnableCopy = (is_copy_constructible_or_void<T>::value && |
| std::is_copy_constructible<E>::value && |
| is_copy_assignable_or_void<T>::value && |
| std::is_copy_assignable<E>::value), |
| bool EnableMove = (is_move_constructible_or_void<T>::value && |
| std::is_move_constructible<E>::value && |
| is_move_assignable_or_void<T>::value && |
| std::is_move_assignable<E>::value)> |
| struct expected_delete_assign_base { |
| expected_delete_assign_base() = default; |
| expected_delete_assign_base(const expected_delete_assign_base &) = default; |
| expected_delete_assign_base(expected_delete_assign_base &&) noexcept = |
| default; |
| expected_delete_assign_base & |
| operator=(const expected_delete_assign_base &) = default; |
| expected_delete_assign_base & |
| operator=(expected_delete_assign_base &&) noexcept = default; |
| }; |
| |
| template <class T, class E> |
| struct expected_delete_assign_base<T, E, true, false> { |
| expected_delete_assign_base() = default; |
| expected_delete_assign_base(const expected_delete_assign_base &) = default; |
| expected_delete_assign_base(expected_delete_assign_base &&) noexcept = |
| default; |
| expected_delete_assign_base & |
| operator=(const expected_delete_assign_base &) = default; |
| expected_delete_assign_base & |
| operator=(expected_delete_assign_base &&) noexcept = delete; |
| }; |
| |
| template <class T, class E> |
| struct expected_delete_assign_base<T, E, false, true> { |
| expected_delete_assign_base() = default; |
| expected_delete_assign_base(const expected_delete_assign_base &) = default; |
| expected_delete_assign_base(expected_delete_assign_base &&) noexcept = |
| default; |
| expected_delete_assign_base & |
| operator=(const expected_delete_assign_base &) = delete; |
| expected_delete_assign_base & |
| operator=(expected_delete_assign_base &&) noexcept = default; |
| }; |
| |
| template <class T, class E> |
| struct expected_delete_assign_base<T, E, false, false> { |
| expected_delete_assign_base() = default; |
| expected_delete_assign_base(const expected_delete_assign_base &) = default; |
| expected_delete_assign_base(expected_delete_assign_base &&) noexcept = |
| default; |
| expected_delete_assign_base & |
| operator=(const expected_delete_assign_base &) = delete; |
| expected_delete_assign_base & |
| operator=(expected_delete_assign_base &&) noexcept = delete; |
| }; |
| |
| // This is needed to be able to construct the expected_default_ctor_base which |
| // follows, while still conditionally deleting the default constructor. |
| struct default_constructor_tag { |
| explicit constexpr default_constructor_tag() = default; |
| }; |
| |
| // expected_default_ctor_base will ensure that expected has a deleted default |
| // consturctor if T is not default constructible. |
| // This specialization is for when T is default constructible |
| template <class T, class E, |
| bool Enable = |
| std::is_default_constructible<T>::value || std::is_void<T>::value> |
| struct expected_default_ctor_base { |
| constexpr expected_default_ctor_base() noexcept = default; |
| constexpr expected_default_ctor_base( |
| expected_default_ctor_base const &) noexcept = default; |
| constexpr expected_default_ctor_base(expected_default_ctor_base &&) noexcept = |
| default; |
| expected_default_ctor_base & |
| operator=(expected_default_ctor_base const &) noexcept = default; |
| expected_default_ctor_base & |
| operator=(expected_default_ctor_base &&) noexcept = default; |
| |
| constexpr explicit expected_default_ctor_base(default_constructor_tag) {} |
| }; |
| |
| // This specialization is for when T is not default constructible |
| template <class T, class E> struct expected_default_ctor_base<T, E, false> { |
| constexpr expected_default_ctor_base() noexcept = delete; |
| constexpr expected_default_ctor_base( |
| expected_default_ctor_base const &) noexcept = default; |
| constexpr expected_default_ctor_base(expected_default_ctor_base &&) noexcept = |
| default; |
| expected_default_ctor_base & |
| operator=(expected_default_ctor_base const &) noexcept = default; |
| expected_default_ctor_base & |
| operator=(expected_default_ctor_base &&) noexcept = default; |
| |
| constexpr explicit expected_default_ctor_base(default_constructor_tag) {} |
| }; |
| } // namespace detail |
| |
| template <class E> class bad_expected_access : public std::exception { |
| public: |
| explicit bad_expected_access(E e) : m_val(std::move(e)) {} |
| |
| virtual const char *what() const noexcept override { |
| return "Bad expected access"; |
| } |
| |
| const E &error() const & { return m_val; } |
| E &error() & { return m_val; } |
| const E &&error() const && { return std::move(m_val); } |
| E &&error() && { return std::move(m_val); } |
| |
| private: |
| E m_val; |
| }; |
| |
| /// An `expected<T, E>` object is an object that contains the storage for |
| /// another object and manages the lifetime of this contained object `T`. |
| /// Alternatively it could contain the storage for another unexpected object |
| /// `E`. The contained object may not be initialized after the expected object |
| /// has been initialized, and may not be destroyed before the expected object |
| /// has been destroyed. The initialization state of the contained object is |
| /// tracked by the expected object. |
| template <class T, class E> |
| class expected : private detail::expected_move_assign_base<T, E>, |
| private detail::expected_delete_ctor_base<T, E>, |
| private detail::expected_delete_assign_base<T, E>, |
| private detail::expected_default_ctor_base<T, E> { |
| static_assert(!std::is_reference<T>::value, "T must not be a reference"); |
| static_assert(!std::is_same<T, std::remove_cv<in_place_t>::type>::value, |
| "T must not be in_place_t"); |
| static_assert(!std::is_same<T, std::remove_cv<unexpect_t>::type>::value, |
| "T must not be unexpect_t"); |
| static_assert( |
| !std::is_same<T, typename std::remove_cv<unexpected<E>>::type>::value, |
| "T must not be unexpected<E>"); |
| static_assert(!std::is_reference<E>::value, "E must not be a reference"); |
| |
| T *valptr() { return std::addressof(this->m_val); } |
| const T *valptr() const { return std::addressof(this->m_val); } |
| unexpected<E> *errptr() { return std::addressof(this->m_unexpect); } |
| const unexpected<E> *errptr() const { |
| return std::addressof(this->m_unexpect); |
| } |
| |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| TL_EXPECTED_11_CONSTEXPR U &val() { |
| return this->m_val; |
| } |
| TL_EXPECTED_11_CONSTEXPR unexpected<E> &err() { return this->m_unexpect; } |
| |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| constexpr const U &val() const { |
| return this->m_val; |
| } |
| constexpr const unexpected<E> &err() const { return this->m_unexpect; } |
| |
| using impl_base = detail::expected_move_assign_base<T, E>; |
| using ctor_base = detail::expected_default_ctor_base<T, E>; |
| |
| public: |
| typedef T value_type; |
| typedef E error_type; |
| typedef unexpected<E> unexpected_type; |
| |
| #if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) && \ |
| !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55) |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto and_then(F &&f) & { |
| return and_then_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto and_then(F &&f) && { |
| return and_then_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> constexpr auto and_then(F &&f) const & { |
| return and_then_impl(*this, std::forward<F>(f)); |
| } |
| |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| template <class F> constexpr auto and_then(F &&f) const && { |
| return and_then_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #endif |
| |
| #else |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR auto |
| and_then(F &&f) & -> decltype(and_then_impl(std::declval<expected &>(), |
| std::forward<F>(f))) { |
| return and_then_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR auto |
| and_then(F &&f) && -> decltype(and_then_impl(std::declval<expected &&>(), |
| std::forward<F>(f))) { |
| return and_then_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> |
| constexpr auto and_then(F &&f) const & -> decltype(and_then_impl( |
| std::declval<expected const &>(), std::forward<F>(f))) { |
| return and_then_impl(*this, std::forward<F>(f)); |
| } |
| |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| template <class F> |
| constexpr auto and_then(F &&f) const && -> decltype(and_then_impl( |
| std::declval<expected const &&>(), std::forward<F>(f))) { |
| return and_then_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #endif |
| #endif |
| |
| #if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) && \ |
| !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55) |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto map(F &&f) & { |
| return expected_map_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto map(F &&f) && { |
| return expected_map_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> constexpr auto map(F &&f) const & { |
| return expected_map_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> constexpr auto map(F &&f) const && { |
| return expected_map_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #else |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR decltype(expected_map_impl( |
| std::declval<expected &>(), std::declval<F &&>())) |
| map(F &&f) & { |
| return expected_map_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR decltype(expected_map_impl(std::declval<expected>(), |
| std::declval<F &&>())) |
| map(F &&f) && { |
| return expected_map_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> |
| constexpr decltype(expected_map_impl(std::declval<const expected &>(), |
| std::declval<F &&>())) |
| map(F &&f) const & { |
| return expected_map_impl(*this, std::forward<F>(f)); |
| } |
| |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| template <class F> |
| constexpr decltype(expected_map_impl(std::declval<const expected &&>(), |
| std::declval<F &&>())) |
| map(F &&f) const && { |
| return expected_map_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #endif |
| #endif |
| |
| #if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) && \ |
| !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55) |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto transform(F &&f) & { |
| return expected_map_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto transform(F &&f) && { |
| return expected_map_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> constexpr auto transform(F &&f) const & { |
| return expected_map_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> constexpr auto transform(F &&f) const && { |
| return expected_map_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #else |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR decltype(expected_map_impl( |
| std::declval<expected &>(), std::declval<F &&>())) |
| transform(F &&f) & { |
| return expected_map_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR decltype(expected_map_impl(std::declval<expected>(), |
| std::declval<F &&>())) |
| transform(F &&f) && { |
| return expected_map_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> |
| constexpr decltype(expected_map_impl(std::declval<const expected &>(), |
| std::declval<F &&>())) |
| transform(F &&f) const & { |
| return expected_map_impl(*this, std::forward<F>(f)); |
| } |
| |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| template <class F> |
| constexpr decltype(expected_map_impl(std::declval<const expected &&>(), |
| std::declval<F &&>())) |
| transform(F &&f) const && { |
| return expected_map_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #endif |
| #endif |
| |
| #if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) && \ |
| !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55) |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto map_error(F &&f) & { |
| return map_error_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto map_error(F &&f) && { |
| return map_error_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> constexpr auto map_error(F &&f) const & { |
| return map_error_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> constexpr auto map_error(F &&f) const && { |
| return map_error_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #else |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR decltype(map_error_impl(std::declval<expected &>(), |
| std::declval<F &&>())) |
| map_error(F &&f) & { |
| return map_error_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR decltype(map_error_impl(std::declval<expected &&>(), |
| std::declval<F &&>())) |
| map_error(F &&f) && { |
| return map_error_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> |
| constexpr decltype(map_error_impl(std::declval<const expected &>(), |
| std::declval<F &&>())) |
| map_error(F &&f) const & { |
| return map_error_impl(*this, std::forward<F>(f)); |
| } |
| |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| template <class F> |
| constexpr decltype(map_error_impl(std::declval<const expected &&>(), |
| std::declval<F &&>())) |
| map_error(F &&f) const && { |
| return map_error_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #endif |
| #endif |
| #if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) && \ |
| !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55) |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto transform_error(F &&f) & { |
| return map_error_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> TL_EXPECTED_11_CONSTEXPR auto transform_error(F &&f) && { |
| return map_error_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> constexpr auto transform_error(F &&f) const & { |
| return map_error_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> constexpr auto transform_error(F &&f) const && { |
| return map_error_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #else |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR decltype(map_error_impl(std::declval<expected &>(), |
| std::declval<F &&>())) |
| transform_error(F &&f) & { |
| return map_error_impl(*this, std::forward<F>(f)); |
| } |
| template <class F> |
| TL_EXPECTED_11_CONSTEXPR decltype(map_error_impl(std::declval<expected &&>(), |
| std::declval<F &&>())) |
| transform_error(F &&f) && { |
| return map_error_impl(std::move(*this), std::forward<F>(f)); |
| } |
| template <class F> |
| constexpr decltype(map_error_impl(std::declval<const expected &>(), |
| std::declval<F &&>())) |
| transform_error(F &&f) const & { |
| return map_error_impl(*this, std::forward<F>(f)); |
| } |
| |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| template <class F> |
| constexpr decltype(map_error_impl(std::declval<const expected &&>(), |
| std::declval<F &&>())) |
| transform_error(F &&f) const && { |
| return map_error_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #endif |
| #endif |
| template <class F> expected TL_EXPECTED_11_CONSTEXPR or_else(F &&f) & { |
| return or_else_impl(*this, std::forward<F>(f)); |
| } |
| |
| template <class F> expected TL_EXPECTED_11_CONSTEXPR or_else(F &&f) && { |
| return or_else_impl(std::move(*this), std::forward<F>(f)); |
| } |
| |
| template <class F> expected constexpr or_else(F &&f) const & { |
| return or_else_impl(*this, std::forward<F>(f)); |
| } |
| |
| #ifndef TL_EXPECTED_NO_CONSTRR |
| template <class F> expected constexpr or_else(F &&f) const && { |
| return or_else_impl(std::move(*this), std::forward<F>(f)); |
| } |
| #endif |
| constexpr expected() = default; |
| constexpr expected(const expected &rhs) = default; |
| constexpr expected(expected &&rhs) = default; |
| expected &operator=(const expected &rhs) = default; |
| expected &operator=(expected &&rhs) = default; |
| |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * = |
| nullptr> |
| constexpr expected(in_place_t, Args &&...args) |
| : impl_base(in_place, std::forward<Args>(args)...), |
| ctor_base(detail::default_constructor_tag{}) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| T, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr expected(in_place_t, std::initializer_list<U> il, Args &&...args) |
| : impl_base(in_place, il, std::forward<Args>(args)...), |
| ctor_base(detail::default_constructor_tag{}) {} |
| |
| template <class G = E, |
| detail::enable_if_t<std::is_constructible<E, const G &>::value> * = |
| nullptr, |
| detail::enable_if_t<!std::is_convertible<const G &, E>::value> * = |
| nullptr> |
| explicit constexpr expected(const unexpected<G> &e) |
| : impl_base(unexpect, e.value()), |
| ctor_base(detail::default_constructor_tag{}) {} |
| |
| template < |
| class G = E, |
| detail::enable_if_t<std::is_constructible<E, const G &>::value> * = |
| nullptr, |
| detail::enable_if_t<std::is_convertible<const G &, E>::value> * = nullptr> |
| constexpr expected(unexpected<G> const &e) |
| : impl_base(unexpect, e.value()), |
| ctor_base(detail::default_constructor_tag{}) {} |
| |
| template < |
| class G = E, |
| detail::enable_if_t<std::is_constructible<E, G &&>::value> * = nullptr, |
| detail::enable_if_t<!std::is_convertible<G &&, E>::value> * = nullptr> |
| explicit constexpr expected(unexpected<G> &&e) noexcept( |
| std::is_nothrow_constructible<E, G &&>::value) |
| : impl_base(unexpect, std::move(e.value())), |
| ctor_base(detail::default_constructor_tag{}) {} |
| |
| template < |
| class G = E, |
| detail::enable_if_t<std::is_constructible<E, G &&>::value> * = nullptr, |
| detail::enable_if_t<std::is_convertible<G &&, E>::value> * = nullptr> |
| constexpr expected(unexpected<G> &&e) noexcept( |
| std::is_nothrow_constructible<E, G &&>::value) |
| : impl_base(unexpect, std::move(e.value())), |
| ctor_base(detail::default_constructor_tag{}) {} |
| |
| template <class... Args, |
| detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * = |
| nullptr> |
| constexpr explicit expected(unexpect_t, Args &&...args) |
| : impl_base(unexpect, std::forward<Args>(args)...), |
| ctor_base(detail::default_constructor_tag{}) {} |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_constructible< |
| E, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| constexpr explicit expected(unexpect_t, std::initializer_list<U> il, |
| Args &&...args) |
| : impl_base(unexpect, il, std::forward<Args>(args)...), |
| ctor_base(detail::default_constructor_tag{}) {} |
| |
| template <class U, class G, |
| detail::enable_if_t<!(std::is_convertible<U const &, T>::value && |
| std::is_convertible<G const &, E>::value)> * = |
| nullptr, |
| detail::expected_enable_from_other<T, E, U, G, const U &, const G &> |
| * = nullptr> |
| explicit TL_EXPECTED_11_CONSTEXPR expected(const expected<U, G> &rhs) |
| : ctor_base(detail::default_constructor_tag{}) { |
| if (rhs.has_value()) { |
| this->construct(*rhs); |
| } else { |
| this->construct_error(rhs.error()); |
| } |
| } |
| |
| template <class U, class G, |
| detail::enable_if_t<(std::is_convertible<U const &, T>::value && |
| std::is_convertible<G const &, E>::value)> * = |
| nullptr, |
| detail::expected_enable_from_other<T, E, U, G, const U &, const G &> |
| * = nullptr> |
| TL_EXPECTED_11_CONSTEXPR expected(const expected<U, G> &rhs) |
| : ctor_base(detail::default_constructor_tag{}) { |
| if (rhs.has_value()) { |
| this->construct(*rhs); |
| } else { |
| this->construct_error(rhs.error()); |
| } |
| } |
| |
| template < |
| class U, class G, |
| detail::enable_if_t<!(std::is_convertible<U &&, T>::value && |
| std::is_convertible<G &&, E>::value)> * = nullptr, |
| detail::expected_enable_from_other<T, E, U, G, U &&, G &&> * = nullptr> |
| explicit TL_EXPECTED_11_CONSTEXPR expected(expected<U, G> &&rhs) |
| : ctor_base(detail::default_constructor_tag{}) { |
| if (rhs.has_value()) { |
| this->construct(std::move(*rhs)); |
| } else { |
| this->construct_error(std::move(rhs.error())); |
| } |
| } |
| |
| template < |
| class U, class G, |
| detail::enable_if_t<(std::is_convertible<U &&, T>::value && |
| std::is_convertible<G &&, E>::value)> * = nullptr, |
| detail::expected_enable_from_other<T, E, U, G, U &&, G &&> * = nullptr> |
| TL_EXPECTED_11_CONSTEXPR expected(expected<U, G> &&rhs) |
| : ctor_base(detail::default_constructor_tag{}) { |
| if (rhs.has_value()) { |
| this->construct(std::move(*rhs)); |
| } else { |
| this->construct_error(std::move(rhs.error())); |
| } |
| } |
| |
| template < |
| class U = T, |
| detail::enable_if_t<!std::is_convertible<U &&, T>::value> * = nullptr, |
| detail::expected_enable_forward_value<T, E, U> * = nullptr> |
| explicit TL_EXPECTED_MSVC2015_CONSTEXPR expected(U &&v) |
| : expected(in_place, std::forward<U>(v)) {} |
| |
| template < |
| class U = T, |
| detail::enable_if_t<std::is_convertible<U &&, T>::value> * = nullptr, |
| detail::expected_enable_forward_value<T, E, U> * = nullptr> |
| TL_EXPECTED_MSVC2015_CONSTEXPR expected(U &&v) |
| : expected(in_place, std::forward<U>(v)) {} |
| |
| template < |
| class U = T, class G = T, |
| detail::enable_if_t<std::is_nothrow_constructible<T, U &&>::value> * = |
| nullptr, |
| detail::enable_if_t<!std::is_void<G>::value> * = nullptr, |
| detail::enable_if_t< |
| (!std::is_same<expected<T, E>, detail::decay_t<U>>::value && |
| !detail::conjunction<std::is_scalar<T>, |
| std::is_same<T, detail::decay_t<U>>>::value && |
| std::is_constructible<T, U>::value && |
| std::is_assignable<G &, U>::value && |
| std::is_nothrow_move_constructible<E>::value)> * = nullptr> |
| expected &operator=(U &&v) { |
| if (has_value()) { |
| val() = std::forward<U>(v); |
| } else { |
| err().~unexpected<E>(); |
| ::new (valptr()) T(std::forward<U>(v)); |
| this->m_has_val = true; |
| } |
| |
| return *this; |
| } |
| |
| template < |
| class U = T, class G = T, |
| detail::enable_if_t<!std::is_nothrow_constructible<T, U &&>::value> * = |
| nullptr, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr, |
| detail::enable_if_t< |
| (!std::is_same<expected<T, E>, detail::decay_t<U>>::value && |
| !detail::conjunction<std::is_scalar<T>, |
| std::is_same<T, detail::decay_t<U>>>::value && |
| std::is_constructible<T, U>::value && |
| std::is_assignable<G &, U>::value && |
| std::is_nothrow_move_constructible<E>::value)> * = nullptr> |
| expected &operator=(U &&v) { |
| if (has_value()) { |
| val() = std::forward<U>(v); |
| } else { |
| auto tmp = std::move(err()); |
| err().~unexpected<E>(); |
| |
| #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED |
| try { |
| ::new (valptr()) T(std::forward<U>(v)); |
| this->m_has_val = true; |
| } catch (...) { |
| err() = std::move(tmp); |
| throw; |
| } |
| #else |
| ::new (valptr()) T(std::forward<U>(v)); |
| this->m_has_val = true; |
| #endif |
| } |
| |
| return *this; |
| } |
| |
| template <class G = E, |
| detail::enable_if_t<std::is_nothrow_copy_constructible<G>::value && |
| std::is_assignable<G &, G>::value> * = nullptr> |
| expected &operator=(const unexpected<G> &rhs) { |
| if (!has_value()) { |
| err() = rhs; |
| } else { |
| this->destroy_val(); |
| ::new (errptr()) unexpected<E>(rhs); |
| this->m_has_val = false; |
| } |
| |
| return *this; |
| } |
| |
| template <class G = E, |
| detail::enable_if_t<std::is_nothrow_move_constructible<G>::value && |
| std::is_move_assignable<G>::value> * = nullptr> |
| expected &operator=(unexpected<G> &&rhs) noexcept { |
| if (!has_value()) { |
| err() = std::move(rhs); |
| } else { |
| this->destroy_val(); |
| ::new (errptr()) unexpected<E>(std::move(rhs)); |
| this->m_has_val = false; |
| } |
| |
| return *this; |
| } |
| |
| template <class... Args, detail::enable_if_t<std::is_nothrow_constructible< |
| T, Args &&...>::value> * = nullptr> |
| void emplace(Args &&...args) { |
| if (has_value()) { |
| val().~T(); |
| } else { |
| err().~unexpected<E>(); |
| this->m_has_val = true; |
| } |
| ::new (valptr()) T(std::forward<Args>(args)...); |
| } |
| |
| template <class... Args, detail::enable_if_t<!std::is_nothrow_constructible< |
| T, Args &&...>::value> * = nullptr> |
| void emplace(Args &&...args) { |
| if (has_value()) { |
| val().~T(); |
| ::new (valptr()) T(std::forward<Args>(args)...); |
| } else { |
| auto tmp = std::move(err()); |
| err().~unexpected<E>(); |
| |
| #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED |
| try { |
| ::new (valptr()) T(std::forward<Args>(args)...); |
| this->m_has_val = true; |
| } catch (...) { |
| err() = std::move(tmp); |
| throw; |
| } |
| #else |
| ::new (valptr()) T(std::forward<Args>(args)...); |
| this->m_has_val = true; |
| #endif |
| } |
| } |
| |
| template <class U, class... Args, |
| detail::enable_if_t<std::is_nothrow_constructible< |
| T, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| void emplace(std::initializer_list<U> il, Args &&...args) { |
| if (has_value()) { |
| T t(il, std::forward<Args>(args)...); |
| val() = std::move(t); |
| } else { |
| err().~unexpected<E>(); |
| ::new (valptr()) T(il, std::forward<Args>(args)...); |
| this->m_has_val = true; |
| } |
| } |
| |
| template <class U, class... Args, |
| detail::enable_if_t<!std::is_nothrow_constructible< |
| T, std::initializer_list<U> &, Args &&...>::value> * = nullptr> |
| void emplace(std::initializer_list<U> il, Args &&...args) { |
| if (has_value()) { |
| T t(il, std::forward<Args>(args)...); |
| val() = std::move(t); |
| } else { |
| auto tmp = std::move(err()); |
| err().~unexpected<E>(); |
| |
| #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED |
| try { |
| ::new (valptr()) T(il, std::forward<Args>(args)...); |
| this->m_has_val = true; |
| } catch (...) { |
| err() = std::move(tmp); |
| throw; |
| } |
| #else |
| ::new (valptr()) T(il, std::forward<Args>(args)...); |
| this->m_has_val = true; |
| #endif |
| } |
| } |
| |
| private: |
| using t_is_void = std::true_type; |
| using t_is_not_void = std::false_type; |
| using t_is_nothrow_move_constructible = std::true_type; |
| using move_constructing_t_can_throw = std::false_type; |
| using e_is_nothrow_move_constructible = std::true_type; |
| using move_constructing_e_can_throw = std::false_type; |
| |
| void swap_where_both_have_value(expected & /*rhs*/, t_is_void) noexcept { |
| // swapping void is a no-op |
| } |
| |
| void swap_where_both_have_value(expected &rhs, t_is_not_void) { |
| using std::swap; |
| swap(val(), rhs.val()); |
| } |
| |
| void swap_where_only_one_has_value(expected &rhs, t_is_void) noexcept( |
| std::is_nothrow_move_constructible<E>::value) { |
| ::new (errptr()) unexpected_type(std::move(rhs.err())); |
| rhs.err().~unexpected_type(); |
| std::swap(this->m_has_val, rhs.m_has_val); |
| } |
| |
| void swap_where_only_one_has_value(expected &rhs, t_is_not_void) { |
| swap_where_only_one_has_value_and_t_is_not_void( |
| rhs, typename std::is_nothrow_move_constructible<T>::type{}, |
| typename std::is_nothrow_move_constructible<E>::type{}); |
| } |
| |
| void swap_where_only_one_has_value_and_t_is_not_void( |
| expected &rhs, t_is_nothrow_move_constructible, |
| e_is_nothrow_move_constructible) noexcept { |
| auto temp = std::move(val()); |
| val().~T(); |
| ::new (errptr()) unexpected_type(std::move(rhs.err())); |
| rhs.err().~unexpected_type(); |
| ::new (rhs.valptr()) T(std::move(temp)); |
| std::swap(this->m_has_val, rhs.m_has_val); |
| } |
| |
| void swap_where_only_one_has_value_and_t_is_not_void( |
| expected &rhs, t_is_nothrow_move_constructible, |
| move_constructing_e_can_throw) { |
| auto temp = std::move(val()); |
| val().~T(); |
| #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED |
| try { |
| ::new (errptr()) unexpected_type(std::move(rhs.err())); |
| rhs.err().~unexpected_type(); |
| ::new (rhs.valptr()) T(std::move(temp)); |
| std::swap(this->m_has_val, rhs.m_has_val); |
| } catch (...) { |
| val() = std::move(temp); |
| throw; |
| } |
| #else |
| ::new (errptr()) unexpected_type(std::move(rhs.err())); |
| rhs.err().~unexpected_type(); |
| ::new (rhs.valptr()) T(std::move(temp)); |
| std::swap(this->m_has_val, rhs.m_has_val); |
| #endif |
| } |
| |
| void swap_where_only_one_has_value_and_t_is_not_void( |
| expected &rhs, move_constructing_t_can_throw, |
| e_is_nothrow_move_constructible) { |
| auto temp = std::move(rhs.err()); |
| rhs.err().~unexpected_type(); |
| #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED |
| try { |
| ::new (rhs.valptr()) T(std::move(val())); |
| val().~T(); |
| ::new (errptr()) unexpected_type(std::move(temp)); |
| std::swap(this->m_has_val, rhs.m_has_val); |
| } catch (...) { |
| rhs.err() = std::move(temp); |
| throw; |
| } |
| #else |
| ::new (rhs.valptr()) T(std::move(val())); |
| val().~T(); |
| ::new (errptr()) unexpected_type(std::move(temp)); |
| std::swap(this->m_has_val, rhs.m_has_val); |
| #endif |
| } |
| |
| public: |
| template <class OT = T, class OE = E> |
| detail::enable_if_t<detail::is_swappable<OT>::value && |
| detail::is_swappable<OE>::value && |
| (std::is_nothrow_move_constructible<OT>::value || |
| std::is_nothrow_move_constructible<OE>::value)> |
| swap(expected &rhs) noexcept( |
| std::is_nothrow_move_constructible<T>::value |
| &&detail::is_nothrow_swappable<T>::value |
| &&std::is_nothrow_move_constructible<E>::value |
| &&detail::is_nothrow_swappable<E>::value) { |
| if (has_value() && rhs.has_value()) { |
| swap_where_both_have_value(rhs, typename std::is_void<T>::type{}); |
| } else if (!has_value() && rhs.has_value()) { |
| rhs.swap(*this); |
| } else if (has_value()) { |
| swap_where_only_one_has_value(rhs, typename std::is_void<T>::type{}); |
| } else { |
| using std::swap; |
| swap(err(), rhs.err()); |
| } |
| } |
| |
| constexpr const T *operator->() const { |
| TL_ASSERT(has_value()); |
| return valptr(); |
| } |
| TL_EXPECTED_11_CONSTEXPR T *operator->() { |
| TL_ASSERT(has_value()); |
| return valptr(); |
| } |
| |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| constexpr const U &operator*() const & { |
| TL_ASSERT(has_value()); |
| return val(); |
| } |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| TL_EXPECTED_11_CONSTEXPR U &operator*() & { |
| TL_ASSERT(has_value()); |
| return val(); |
| } |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| constexpr const U &&operator*() const && { |
| TL_ASSERT(has_value()); |
| return std::move(val()); |
| } |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| TL_EXPECTED_11_CONSTEXPR U &&operator*() && { |
| TL_ASSERT(has_value()); |
| return std::move(val()); |
| } |
| |
| constexpr bool has_value() const noexcept { return this->m_has_val; } |
| constexpr explicit operator bool() const noexcept { return this->m_has_val; } |
| |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| TL_EXPECTED_11_CONSTEXPR const U &value() const & { |
| if (!has_value()) |
| detail::throw_exception(bad_expected_access<E>(err().value())); |
| return val(); |
| } |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| TL_EXPECTED_11_CONSTEXPR U &value() & { |
| if (!has_value()) |
| detail::throw_exception(bad_expected_access<E>(err().value())); |
| return val(); |
| } |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| TL_EXPECTED_11_CONSTEXPR const U &&value() const && { |
| if (!has_value()) |
| detail::throw_exception(bad_expected_access<E>(std::move(err()).value())); |
| return std::move(val()); |
| } |
| template <class U = T, |
| detail::enable_if_t<!std::is_void<U>::value> * = nullptr> |
| TL_EXPECTED_11_CONSTEXPR U &&value() && { |
| if (!has_value()) |
| detail::throw_exception(bad_expected_access<E>(std::move(err()).value())); |
| return std::move(val()); |
| } |
| |
| constexpr const E &error() const & { |
| TL_ASSERT(!has_value()); |
| return err().value(); |
| } |
| TL_EXPECTED_11_CONSTEXPR E &error() & { |
| TL_ASSERT(!has_value()); |
| return err().value(); |
| } |
| constexpr const E &&error() const && { |
| TL_ASSERT(!has_value()); |
| return std::move(err().value()); |
| } |
| TL_EXPECTED_11_CONSTEXPR E &&error() && { |
| TL_ASSERT(!has_value()); |
| return std::move(err().value()); |
| } |
| |
| template <class U> constexpr T value_or(U &&v) const & { |
| static_assert(std::is_copy_constructible<T>::value && |
| std::is_convertible<U &&, T>::value, |
| "T must be copy-constructible and convertible to from U&&"); |
| return bool(*this) ? **this : static_cast<T>(std::forward<U>(v)); |
| } |
| template <class U> TL_EXPECTED_11_CONSTEXPR T value_or(U &&v) && { |
| static_assert(std::is_move_constructible<T>::value && |
| std::is_convertible<U &&, T>::value, |
| "T must be move-constructible and convertible to from U&&"); |
| return bool(*this) ? std::move(**this) : static_cast<T>(std::forward<U>(v)); |
| } |
| }; |
| |
| namespace detail { |
| template <class Exp> using exp_t = typename detail::decay_t<Exp>::value_type; |
| template <class Exp> using err_t = typename detail::decay_t<Exp>::error_type; |
| template <class Exp, class Ret> using ret_t = expected<Ret, err_t<Exp>>; |
| |
| #ifdef TL_EXPECTED_CXX14 |
| template <class Exp, class F, |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| *std::declval<Exp>()))> |
| constexpr auto and_then_impl(Exp &&exp, F &&f) { |
| static_assert(detail::is_expected<Ret>::value, "F must return an expected"); |
| |
| return exp.has_value() |
| ? detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp)) |
| : Ret(unexpect, std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>()))> |
| constexpr auto and_then_impl(Exp &&exp, F &&f) { |
| static_assert(detail::is_expected<Ret>::value, "F must return an expected"); |
| |
| return exp.has_value() ? detail::invoke(std::forward<F>(f)) |
| : Ret(unexpect, std::forward<Exp>(exp).error()); |
| } |
| #else |
| template <class> struct TC; |
| template <class Exp, class F, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| *std::declval<Exp>())), |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr> |
| auto and_then_impl(Exp &&exp, F &&f) -> Ret { |
| static_assert(detail::is_expected<Ret>::value, "F must return an expected"); |
| |
| return exp.has_value() |
| ? detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp)) |
| : Ret(unexpect, std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| class Ret = decltype(detail::invoke(std::declval<F>())), |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr> |
| constexpr auto and_then_impl(Exp &&exp, F &&f) -> Ret { |
| static_assert(detail::is_expected<Ret>::value, "F must return an expected"); |
| |
| return exp.has_value() ? detail::invoke(std::forward<F>(f)) |
| : Ret(unexpect, std::forward<Exp>(exp).error()); |
| } |
| #endif |
| |
| #ifdef TL_EXPECTED_CXX14 |
| template <class Exp, class F, |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| *std::declval<Exp>())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| constexpr auto expected_map_impl(Exp &&exp, F &&f) { |
| using result = ret_t<Exp, detail::decay_t<Ret>>; |
| return exp.has_value() ? result(detail::invoke(std::forward<F>(f), |
| *std::forward<Exp>(exp))) |
| : result(unexpect, std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| *std::declval<Exp>())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| auto expected_map_impl(Exp &&exp, F &&f) { |
| using result = expected<void, err_t<Exp>>; |
| if (exp.has_value()) { |
| detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp)); |
| return result(); |
| } |
| |
| return result(unexpect, std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| constexpr auto expected_map_impl(Exp &&exp, F &&f) { |
| using result = ret_t<Exp, detail::decay_t<Ret>>; |
| return exp.has_value() ? result(detail::invoke(std::forward<F>(f))) |
| : result(unexpect, std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| auto expected_map_impl(Exp &&exp, F &&f) { |
| using result = expected<void, err_t<Exp>>; |
| if (exp.has_value()) { |
| detail::invoke(std::forward<F>(f)); |
| return result(); |
| } |
| |
| return result(unexpect, std::forward<Exp>(exp).error()); |
| } |
| #else |
| template <class Exp, class F, |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| *std::declval<Exp>())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| |
| constexpr auto expected_map_impl(Exp &&exp, F &&f) |
| -> ret_t<Exp, detail::decay_t<Ret>> { |
| using result = ret_t<Exp, detail::decay_t<Ret>>; |
| |
| return exp.has_value() ? result(detail::invoke(std::forward<F>(f), |
| *std::forward<Exp>(exp))) |
| : result(unexpect, std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| *std::declval<Exp>())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| |
| auto expected_map_impl(Exp &&exp, F &&f) -> expected<void, err_t<Exp>> { |
| if (exp.has_value()) { |
| detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp)); |
| return {}; |
| } |
| |
| return unexpected<err_t<Exp>>(std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| |
| constexpr auto expected_map_impl(Exp &&exp, F &&f) |
| -> ret_t<Exp, detail::decay_t<Ret>> { |
| using result = ret_t<Exp, detail::decay_t<Ret>>; |
| |
| return exp.has_value() ? result(detail::invoke(std::forward<F>(f))) |
| : result(unexpect, std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| |
| auto expected_map_impl(Exp &&exp, F &&f) -> expected<void, err_t<Exp>> { |
| if (exp.has_value()) { |
| detail::invoke(std::forward<F>(f)); |
| return {}; |
| } |
| |
| return unexpected<err_t<Exp>>(std::forward<Exp>(exp).error()); |
| } |
| #endif |
| |
| #if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) && \ |
| !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55) |
| template <class Exp, class F, |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| constexpr auto map_error_impl(Exp &&exp, F &&f) { |
| using result = expected<exp_t<Exp>, detail::decay_t<Ret>>; |
| return exp.has_value() |
| ? result(*std::forward<Exp>(exp)) |
| : result(unexpect, detail::invoke(std::forward<F>(f), |
| std::forward<Exp>(exp).error())); |
| } |
| template <class Exp, class F, |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| auto map_error_impl(Exp &&exp, F &&f) { |
| using result = expected<exp_t<Exp>, monostate>; |
| if (exp.has_value()) { |
| return result(*std::forward<Exp>(exp)); |
| } |
| |
| detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error()); |
| return result(unexpect, monostate{}); |
| } |
| template <class Exp, class F, |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| constexpr auto map_error_impl(Exp &&exp, F &&f) { |
| using result = expected<exp_t<Exp>, detail::decay_t<Ret>>; |
| return exp.has_value() |
| ? result() |
| : result(unexpect, detail::invoke(std::forward<F>(f), |
| std::forward<Exp>(exp).error())); |
| } |
| template <class Exp, class F, |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| auto map_error_impl(Exp &&exp, F &&f) { |
| using result = expected<exp_t<Exp>, monostate>; |
| if (exp.has_value()) { |
| return result(); |
| } |
| |
| detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error()); |
| return result(unexpect, monostate{}); |
| } |
| #else |
| template <class Exp, class F, |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| constexpr auto map_error_impl(Exp &&exp, F &&f) |
| -> expected<exp_t<Exp>, detail::decay_t<Ret>> { |
| using result = expected<exp_t<Exp>, detail::decay_t<Ret>>; |
| |
| return exp.has_value() |
| ? result(*std::forward<Exp>(exp)) |
| : result(unexpect, detail::invoke(std::forward<F>(f), |
| std::forward<Exp>(exp).error())); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| auto map_error_impl(Exp &&exp, F &&f) -> expected<exp_t<Exp>, monostate> { |
| using result = expected<exp_t<Exp>, monostate>; |
| if (exp.has_value()) { |
| return result(*std::forward<Exp>(exp)); |
| } |
| |
| detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error()); |
| return result(unexpect, monostate{}); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| constexpr auto map_error_impl(Exp &&exp, F &&f) |
| -> expected<exp_t<Exp>, detail::decay_t<Ret>> { |
| using result = expected<exp_t<Exp>, detail::decay_t<Ret>>; |
| |
| return exp.has_value() |
| ? result() |
| : result(unexpect, detail::invoke(std::forward<F>(f), |
| std::forward<Exp>(exp).error())); |
| } |
| |
| template <class Exp, class F, |
| detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| auto map_error_impl(Exp &&exp, F &&f) -> expected<exp_t<Exp>, monostate> { |
| using result = expected<exp_t<Exp>, monostate>; |
| if (exp.has_value()) { |
| return result(); |
| } |
| |
| detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error()); |
| return result(unexpect, monostate{}); |
| } |
| #endif |
| |
| #ifdef TL_EXPECTED_CXX14 |
| template <class Exp, class F, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| constexpr auto or_else_impl(Exp &&exp, F &&f) { |
| static_assert(detail::is_expected<Ret>::value, "F must return an expected"); |
| return exp.has_value() ? std::forward<Exp>(exp) |
| : detail::invoke(std::forward<F>(f), |
| std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| detail::decay_t<Exp> or_else_impl(Exp &&exp, F &&f) { |
| return exp.has_value() ? std::forward<Exp>(exp) |
| : (detail::invoke(std::forward<F>(f), |
| std::forward<Exp>(exp).error()), |
| std::forward<Exp>(exp)); |
| } |
| #else |
| template <class Exp, class F, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr> |
| auto or_else_impl(Exp &&exp, F &&f) -> Ret { |
| static_assert(detail::is_expected<Ret>::value, "F must return an expected"); |
| return exp.has_value() ? std::forward<Exp>(exp) |
| : detail::invoke(std::forward<F>(f), |
| std::forward<Exp>(exp).error()); |
| } |
| |
| template <class Exp, class F, |
| class Ret = decltype(detail::invoke(std::declval<F>(), |
| std::declval<Exp>().error())), |
| detail::enable_if_t<std::is_void<Ret>::value> * = nullptr> |
| detail::decay_t<Exp> or_else_impl(Exp &&exp, F &&f) { |
| return exp.has_value() ? std::forward<Exp>(exp) |
| : (detail::invoke(std::forward<F>(f), |
| std::forward<Exp>(exp).error()), |
| std::forward<Exp>(exp)); |
| } |
| #endif |
| } // namespace detail |
| |
| template <class T, class E, class U, class F> |
| constexpr bool operator==(const expected<T, E> &lhs, |
| const expected<U, F> &rhs) { |
| return (lhs.has_value() != rhs.has_value()) |
| ? false |
| : (!lhs.has_value() ? lhs.error() == rhs.error() : *lhs == *rhs); |
| } |
| template <class T, class E, class U, class F> |
| constexpr bool operator!=(const expected<T, E> &lhs, |
| const expected<U, F> &rhs) { |
| return (lhs.has_value() != rhs.has_value()) |
| ? true |
| : (!lhs.has_value() ? lhs.error() != rhs.error() : *lhs != *rhs); |
| } |
| template <class E, class F> |
| constexpr bool operator==(const expected<void, E> &lhs, |
| const expected<void, F> &rhs) { |
| return (lhs.has_value() != rhs.has_value()) |
| ? false |
| : (!lhs.has_value() ? lhs.error() == rhs.error() : true); |
| } |
| template <class E, class F> |
| constexpr bool operator!=(const expected<void, E> &lhs, |
| const expected<void, F> &rhs) { |
| return (lhs.has_value() != rhs.has_value()) |
| ? true |
| : (!lhs.has_value() ? lhs.error() == rhs.error() : false); |
| } |
| |
| template <class T, class E, class U> |
| constexpr bool operator==(const expected<T, E> &x, const U &v) { |
| return x.has_value() ? *x == v : false; |
| } |
| template <class T, class E, class U> |
| constexpr bool operator==(const U &v, const expected<T, E> &x) { |
| return x.has_value() ? *x == v : false; |
| } |
| template <class T, class E, class U> |
| constexpr bool operator!=(const expected<T, E> &x, const U &v) { |
| return x.has_value() ? *x != v : true; |
| } |
| template <class T, class E, class U> |
| constexpr bool operator!=(const U &v, const expected<T, E> &x) { |
| return x.has_value() ? *x != v : true; |
| } |
| |
| template <class T, class E> |
| constexpr bool operator==(const expected<T, E> &x, const unexpected<E> &e) { |
| return x.has_value() ? false : x.error() == e.value(); |
| } |
| template <class T, class E> |
| constexpr bool operator==(const unexpected<E> &e, const expected<T, E> &x) { |
| return x.has_value() ? false : x.error() == e.value(); |
| } |
| template <class T, class E> |
| constexpr bool operator!=(const expected<T, E> &x, const unexpected<E> &e) { |
| return x.has_value() ? true : x.error() != e.value(); |
| } |
| template <class T, class E> |
| constexpr bool operator!=(const unexpected<E> &e, const expected<T, E> &x) { |
| return x.has_value() ? true : x.error() != e.value(); |
| } |
| |
| template <class T, class E, |
| detail::enable_if_t<(std::is_void<T>::value || |
| std::is_move_constructible<T>::value) && |
| detail::is_swappable<T>::value && |
| std::is_move_constructible<E>::value && |
| detail::is_swappable<E>::value> * = nullptr> |
| void swap(expected<T, E> &lhs, |
| expected<T, E> &rhs) noexcept(noexcept(lhs.swap(rhs))) { |
| lhs.swap(rhs); |
| } |
| } // namespace tl |
| |
| #endif |
| // NOLINTEND |
| // clang-format on |