forked from TartanLlama/expected
2675ce3cd4
* Convert tabs to spaces * Remove extra semicolons in test * Fix warnings in test -Wreturn-type -Wunused-parameter -Wunused-value * Fix -Wunused-variable warning in test The variable 'failptr' is unused. From looking at the other variables in the test case, it seems the fix is to first remove 'failptr' and then rename 'efail' to 'failptr'. * Fix -Wunused-variable warning in test * Fix -Wmacro-redefined warning in test STATIC_REQUIRE has a previous definition in catch2/catch.hpp.
2360 lines
88 KiB
C++
2360 lines
88 KiB
C++
///
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// expected - An implementation of std::expected with extensions
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// Written in 2017 by Simon Brand (simonrbrand@gmail.com, @TartanLlama)
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//
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// Documentation available at http://tl.tartanllama.xyz/
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//
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// To the extent possible under law, the author(s) have dedicated all
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// copyright and related and neighboring rights to this software to the
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// public domain worldwide. This software is distributed without any warranty.
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//
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// You should have received a copy of the CC0 Public Domain Dedication
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// along with this software. If not, see
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// <http://creativecommons.org/publicdomain/zero/1.0/>.
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///
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#ifndef TL_EXPECTED_HPP
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#define TL_EXPECTED_HPP
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#define TL_EXPECTED_VERSION_MAJOR 1
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#define TL_EXPECTED_VERSION_MINOR 0
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#define TL_EXPECTED_VERSION_PATCH 1
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#include <exception>
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#include <functional>
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#include <type_traits>
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#include <utility>
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#if defined(__EXCEPTIONS) || defined(_CPPUNWIND)
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#define TL_EXPECTED_EXCEPTIONS_ENABLED
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#endif
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#if (defined(_MSC_VER) && _MSC_VER == 1900)
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#define TL_EXPECTED_MSVC2015
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#define TL_EXPECTED_MSVC2015_CONSTEXPR
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#else
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#define TL_EXPECTED_MSVC2015_CONSTEXPR constexpr
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#endif
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#if (defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ <= 9 && \
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!defined(__clang__))
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#define TL_EXPECTED_GCC49
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#endif
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#if (defined(__GNUC__) && __GNUC__ == 5 && __GNUC_MINOR__ <= 4 && \
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!defined(__clang__))
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#define TL_EXPECTED_GCC54
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#endif
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#if (defined(__GNUC__) && __GNUC__ == 5 && __GNUC_MINOR__ <= 5 && \
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!defined(__clang__))
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#define TL_EXPECTED_GCC55
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#endif
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#if (defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ <= 9 && \
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!defined(__clang__))
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// GCC < 5 doesn't support overloading on const&& for member functions
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#define TL_EXPECTED_NO_CONSTRR
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// GCC < 5 doesn't support some standard C++11 type traits
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#define TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) \
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std::has_trivial_copy_constructor<T>
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#define TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T) \
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std::has_trivial_copy_assign<T>
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// This one will be different for GCC 5.7 if it's ever supported
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#define TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T) \
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std::is_trivially_destructible<T>
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// GCC 5 < v < 8 has a bug in is_trivially_copy_constructible which breaks std::vector
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// for non-copyable types
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#elif (defined(__GNUC__) && __GNUC__ < 8 && \
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!defined(__clang__))
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#ifndef TL_GCC_LESS_8_TRIVIALLY_COPY_CONSTRUCTIBLE_MUTEX
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#define TL_GCC_LESS_8_TRIVIALLY_COPY_CONSTRUCTIBLE_MUTEX
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namespace tl {
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namespace detail {
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template<class T>
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struct is_trivially_copy_constructible : std::is_trivially_copy_constructible<T>{};
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#ifdef _GLIBCXX_VECTOR
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template<class T, class A>
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struct is_trivially_copy_constructible<std::vector<T,A>>
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: std::false_type{};
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#endif
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}
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}
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#endif
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#define TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) \
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tl::detail::is_trivially_copy_constructible<T>
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#define TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T) \
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std::is_trivially_copy_assignable<T>
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#define TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T) std::is_trivially_destructible<T>
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#else
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#define TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) \
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std::is_trivially_copy_constructible<T>
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#define TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T) \
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std::is_trivially_copy_assignable<T>
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#define TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T) \
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std::is_trivially_destructible<T>
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#endif
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#if __cplusplus > 201103L
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#define TL_EXPECTED_CXX14
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#endif
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#ifdef TL_EXPECTED_GCC49
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#define TL_EXPECTED_GCC49_CONSTEXPR
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#else
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#define TL_EXPECTED_GCC49_CONSTEXPR constexpr
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#endif
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#if (__cplusplus == 201103L || defined(TL_EXPECTED_MSVC2015) || \
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defined(TL_EXPECTED_GCC49))
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#define TL_EXPECTED_11_CONSTEXPR
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#else
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#define TL_EXPECTED_11_CONSTEXPR constexpr
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#endif
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namespace tl {
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template <class T, class E> class expected;
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#ifndef TL_MONOSTATE_INPLACE_MUTEX
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#define TL_MONOSTATE_INPLACE_MUTEX
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class monostate {};
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struct in_place_t {
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explicit in_place_t() = default;
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};
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static constexpr in_place_t in_place{};
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#endif
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template <class E> class unexpected {
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public:
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static_assert(!std::is_same<E, void>::value, "E must not be void");
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unexpected() = delete;
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constexpr explicit unexpected(const E &e) : m_val(e) {}
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constexpr explicit unexpected(E &&e) : m_val(std::move(e)) {}
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template <class... Args, typename std::enable_if<std::is_constructible<
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E, Args &&...>::value>::type * = nullptr>
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constexpr explicit unexpected(Args &&...args)
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: m_val(std::forward<Args>(args)...) {}
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template <
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class U, class... Args,
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typename std::enable_if<std::is_constructible<
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E, std::initializer_list<U> &, Args &&...>::value>::type * = nullptr>
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constexpr explicit unexpected(std::initializer_list<U> l,
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Args &&...args)
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: m_val(l, std::forward<Args>(args)...) {}
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constexpr const E &value() const & { return m_val; }
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TL_EXPECTED_11_CONSTEXPR E &value() & { return m_val; }
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TL_EXPECTED_11_CONSTEXPR E &&value() && { return std::move(m_val); }
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constexpr const E &&value() const && { return std::move(m_val); }
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private:
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E m_val;
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};
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#ifdef __cpp_deduction_guides
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template<class E>
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unexpected(E) -> unexpected<E>;
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#endif
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template <class E>
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constexpr bool operator==(const unexpected<E> &lhs, const unexpected<E> &rhs) {
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return lhs.value() == rhs.value();
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}
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template <class E>
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constexpr bool operator!=(const unexpected<E> &lhs, const unexpected<E> &rhs) {
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return lhs.value() != rhs.value();
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}
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template <class E>
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constexpr bool operator<(const unexpected<E> &lhs, const unexpected<E> &rhs) {
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return lhs.value() < rhs.value();
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}
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template <class E>
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constexpr bool operator<=(const unexpected<E> &lhs, const unexpected<E> &rhs) {
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return lhs.value() <= rhs.value();
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}
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template <class E>
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constexpr bool operator>(const unexpected<E> &lhs, const unexpected<E> &rhs) {
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return lhs.value() > rhs.value();
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}
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template <class E>
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constexpr bool operator>=(const unexpected<E> &lhs, const unexpected<E> &rhs) {
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return lhs.value() >= rhs.value();
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}
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template <class E>
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unexpected<typename std::decay<E>::type> make_unexpected(E &&e) {
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return unexpected<typename std::decay<E>::type>(std::forward<E>(e));
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}
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struct unexpect_t {
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unexpect_t() = default;
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};
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static constexpr unexpect_t unexpect{};
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namespace detail {
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template<typename E>
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[[noreturn]] TL_EXPECTED_11_CONSTEXPR void throw_exception(E &&e) {
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#ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
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throw std::forward<E>(e);
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#else
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#ifdef _MSC_VER
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__assume(0);
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#else
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__builtin_unreachable();
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#endif
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#endif
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}
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#ifndef TL_TRAITS_MUTEX
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#define TL_TRAITS_MUTEX
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// C++14-style aliases for brevity
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template <class T> using remove_const_t = typename std::remove_const<T>::type;
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template <class T>
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using remove_reference_t = typename std::remove_reference<T>::type;
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template <class T> using decay_t = typename std::decay<T>::type;
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template <bool E, class T = void>
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using enable_if_t = typename std::enable_if<E, T>::type;
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template <bool B, class T, class F>
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using conditional_t = typename std::conditional<B, T, F>::type;
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// std::conjunction from C++17
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template <class...> struct conjunction : std::true_type {};
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template <class B> struct conjunction<B> : B {};
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template <class B, class... Bs>
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struct conjunction<B, Bs...>
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: std::conditional<bool(B::value), conjunction<Bs...>, B>::type {};
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#if defined(_LIBCPP_VERSION) && __cplusplus == 201103L
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#define TL_TRAITS_LIBCXX_MEM_FN_WORKAROUND
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#endif
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// In C++11 mode, there's an issue in libc++'s std::mem_fn
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// which results in a hard-error when using it in a noexcept expression
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// in some cases. This is a check to workaround the common failing case.
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#ifdef TL_TRAITS_LIBCXX_MEM_FN_WORKAROUND
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template <class T> struct is_pointer_to_non_const_member_func : std::false_type {};
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template <class T, class Ret, class... Args>
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struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...)> : std::true_type {};
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template <class T, class Ret, class... Args>
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struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...)&> : std::true_type {};
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template <class T, class Ret, class... Args>
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struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...) &&> : std::true_type {};
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template <class T, class Ret, class... Args>
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struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...) volatile> : std::true_type {};
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template <class T, class Ret, class... Args>
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struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...) volatile &> : std::true_type {};
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template <class T, class Ret, class... Args>
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struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...) volatile &&> : std::true_type {};
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template <class T> struct is_const_or_const_ref : std::false_type {};
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template <class T> struct is_const_or_const_ref<T const&> : std::true_type {};
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template <class T> struct is_const_or_const_ref<T const> : std::true_type {};
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#endif
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// std::invoke from C++17
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// https://stackoverflow.com/questions/38288042/c11-14-invoke-workaround
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template <typename Fn, typename... Args,
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#ifdef TL_TRAITS_LIBCXX_MEM_FN_WORKAROUND
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typename = enable_if_t<!(is_pointer_to_non_const_member_func<Fn>::value
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&& is_const_or_const_ref<Args...>::value)>,
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#endif
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typename = enable_if_t<std::is_member_pointer<decay_t<Fn>>::value>,
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int = 0>
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constexpr auto invoke(Fn && f, Args && ... args) noexcept(
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noexcept(std::mem_fn(f)(std::forward<Args>(args)...)))
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-> decltype(std::mem_fn(f)(std::forward<Args>(args)...)) {
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return std::mem_fn(f)(std::forward<Args>(args)...);
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}
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template <typename Fn, typename... Args,
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typename = enable_if_t<!std::is_member_pointer<decay_t<Fn>>::value>>
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constexpr auto invoke(Fn && f, Args && ... args) noexcept(
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noexcept(std::forward<Fn>(f)(std::forward<Args>(args)...)))
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-> decltype(std::forward<Fn>(f)(std::forward<Args>(args)...)) {
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return std::forward<Fn>(f)(std::forward<Args>(args)...);
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}
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// std::invoke_result from C++17
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template <class F, class, class... Us> struct invoke_result_impl;
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template <class F, class... Us>
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struct invoke_result_impl<
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F, decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...), void()),
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Us...> {
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using type = decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...));
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};
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template <class F, class... Us>
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using invoke_result = invoke_result_impl<F, void, Us...>;
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template <class F, class... Us>
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using invoke_result_t = typename invoke_result<F, Us...>::type;
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#if defined(_MSC_VER) && _MSC_VER <= 1900
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// TODO make a version which works with MSVC 2015
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template <class T, class U = T> struct is_swappable : std::true_type {};
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template <class T, class U = T> struct is_nothrow_swappable : std::true_type {};
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#else
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// https://stackoverflow.com/questions/26744589/what-is-a-proper-way-to-implement-is-swappable-to-test-for-the-swappable-concept
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namespace swap_adl_tests {
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// if swap ADL finds this then it would call std::swap otherwise (same
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// signature)
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struct tag {};
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template <class T> tag swap(T&, T&);
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template <class T, std::size_t N> tag swap(T(&a)[N], T(&b)[N]);
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// helper functions to test if an unqualified swap is possible, and if it
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// becomes std::swap
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template <class, class> std::false_type can_swap(...) noexcept(false);
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template <class T, class U,
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class = decltype(swap(std::declval<T&>(), std::declval<U&>()))>
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std::true_type can_swap(int) noexcept(noexcept(swap(std::declval<T&>(),
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std::declval<U&>())));
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template <class, class> std::false_type uses_std(...);
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template <class T, class U>
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std::is_same<decltype(swap(std::declval<T&>(), std::declval<U&>())), tag>
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uses_std(int);
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template <class T>
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struct is_std_swap_noexcept
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: std::integral_constant<bool,
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std::is_nothrow_move_constructible<T>::value&&
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std::is_nothrow_move_assignable<T>::value> {};
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template <class T, std::size_t N>
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struct is_std_swap_noexcept<T[N]> : is_std_swap_noexcept<T> {};
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template <class T, class U>
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struct is_adl_swap_noexcept
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: std::integral_constant<bool, noexcept(can_swap<T, U>(0))> {};
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} // namespace swap_adl_tests
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template <class T, class U = T>
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struct is_swappable
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: std::integral_constant<
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bool,
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decltype(detail::swap_adl_tests::can_swap<T, U>(0))::value &&
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(!decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value ||
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(std::is_move_assignable<T>::value &&
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std::is_move_constructible<T>::value))> {};
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template <class T, std::size_t N>
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struct is_swappable<T[N], T[N]>
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: std::integral_constant<
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bool,
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decltype(detail::swap_adl_tests::can_swap<T[N], T[N]>(0))::value &&
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(!decltype(
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detail::swap_adl_tests::uses_std<T[N], T[N]>(0))::value ||
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is_swappable<T, T>::value)> {};
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template <class T, class U = T>
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struct is_nothrow_swappable
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: std::integral_constant<
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bool,
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is_swappable<T, U>::value &&
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((decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value
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&& detail::swap_adl_tests::is_std_swap_noexcept<T>::value) ||
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(!decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value &&
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detail::swap_adl_tests::is_adl_swap_noexcept<T,
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U>::value))> {
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};
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#endif
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#endif
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// Trait for checking if a type is a tl::expected
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template <class T> struct is_expected_impl : std::false_type {};
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template <class T, class E>
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struct is_expected_impl<expected<T, E>> : std::true_type {};
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template <class T> using is_expected = is_expected_impl<decay_t<T>>;
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template <class T, class E, class U>
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using expected_enable_forward_value = detail::enable_if_t<
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std::is_constructible<T, U &&>::value &&
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!std::is_same<detail::decay_t<U>, in_place_t>::value &&
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!std::is_same<expected<T, E>, detail::decay_t<U>>::value &&
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!std::is_same<unexpected<E>, detail::decay_t<U>>::value>;
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template <class T, class E, class U, class G, class UR, class GR>
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using expected_enable_from_other = detail::enable_if_t<
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std::is_constructible<T, UR>::value &&
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std::is_constructible<E, GR>::value &&
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!std::is_constructible<T, expected<U, G> &>::value &&
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!std::is_constructible<T, expected<U, G> &&>::value &&
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!std::is_constructible<T, const expected<U, G> &>::value &&
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!std::is_constructible<T, const expected<U, G> &&>::value &&
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!std::is_convertible<expected<U, G> &, T>::value &&
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!std::is_convertible<expected<U, G> &&, T>::value &&
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!std::is_convertible<const expected<U, G> &, T>::value &&
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!std::is_convertible<const expected<U, G> &&, T>::value>;
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template <class T, class U>
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using is_void_or = conditional_t<std::is_void<T>::value, std::true_type, U>;
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template <class T>
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using is_copy_constructible_or_void =
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is_void_or<T, std::is_copy_constructible<T>>;
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template <class T>
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using is_move_constructible_or_void =
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is_void_or<T, std::is_move_constructible<T>>;
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template <class T>
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using is_copy_assignable_or_void =
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is_void_or<T, std::is_copy_assignable<T>>;
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template <class T>
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using is_move_assignable_or_void =
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is_void_or<T, std::is_move_assignable<T>>;
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|
|
|
} // 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> {
|
|
TL_EXPECTED_MSVC2015_CONSTEXPR 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(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
|
|
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 { return valptr(); }
|
|
TL_EXPECTED_11_CONSTEXPR T *operator->() { return valptr(); }
|
|
|
|
template <class U = T,
|
|
detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
|
|
constexpr const U &operator*() const & {
|
|
return val();
|
|
}
|
|
template <class U = T,
|
|
detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
|
|
TL_EXPECTED_11_CONSTEXPR U &operator*() & {
|
|
return val();
|
|
}
|
|
template <class U = T,
|
|
detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
|
|
constexpr const U &&operator*() const && {
|
|
return std::move(val());
|
|
}
|
|
template <class U = T,
|
|
detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
|
|
TL_EXPECTED_11_CONSTEXPR U &&operator*() && {
|
|
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 & { return err().value(); }
|
|
TL_EXPECTED_11_CONSTEXPR E &error() & { return err().value(); }
|
|
constexpr const E &&error() const && { return std::move(err().value()); }
|
|
TL_EXPECTED_11_CONSTEXPR E &&error() && { 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
|