// The MIT License (MIT) // Copyright (c) 2013-2019 Rapptz, ThePhD and contributors // Permission is hereby granted, free of charge, to any person obtaining a copy of // this software and associated documentation files (the "Software"), to deal in // the Software without restriction, including without limitation the rights to // use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of // the Software, and to permit persons to whom the Software is furnished to do so, // subject to the following conditions: // The above copyright notice and this permission notice shall be included in all // copies or substantial portions of the Software. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS // FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR // COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER // IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. // Taken from: TartanLlama/optional on Github, because // holy shit am I done dealing with C++11 constexpr /// // optional - An implementation of std::optional with extensions // Written in 2017 by Simon Brand (@TartanLlama) // // To the extent possible under law, the author(s) have dedicated all // copyright and related and neighboring rights to this software to the // public domain worldwide. This software is distributed without any warranty. // // You should have received a copy of the CC0 Public Domain Dedication // along with this software. If not, see // . /// #ifndef SOL_TL_OPTIONAL_HPP #define SOL_TL_OPTIONAL_HPP #include "in_place.hpp" #define SOL_TL_OPTIONAL_VERSION_MAJOR 0 #define SOL_TL_OPTIONAL_VERSION_MINOR 5 #include #include #include #include #include #include #include #if (defined(_MSC_VER) && _MSC_VER == 1900) #define SOL_TL_OPTIONAL_MSVC2015 #endif #if (defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ <= 9 && !defined(__clang__)) #define SOL_TL_OPTIONAL_GCC49 #endif #if (defined(__GNUC__) && __GNUC__ == 5 && __GNUC_MINOR__ <= 4 && !defined(__clang__)) #define SOL_TL_OPTIONAL_GCC54 #endif #if (defined(__GNUC__) && __GNUC__ == 5 && __GNUC_MINOR__ <= 5 && !defined(__clang__)) #define SOL_TL_OPTIONAL_GCC55 #endif #if (defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ <= 9 && !defined(__clang__)) // GCC < 5 doesn't support overloading on const&& for member functions #define SOL_TL_OPTIONAL_NO_CONSTRR // GCC < 5 doesn't support some standard C++11 type traits #define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) std::has_trivial_copy_constructor::value #define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_ASSIGNABLE(T) std::has_trivial_copy_assign::value // This one will be different for GCC 5.7 if it's ever supported #define SOL_TL_OPTIONAL_IS_TRIVIALLY_DESTRUCTIBLE(T) std::is_trivially_destructible::value // GCC 5 < v < 8 has a bug in is_trivially_copy_constructible which breaks std::vector // for non-copyable types #elif (defined(__GNUC__) && __GNUC__ < 8 && !defined(__clang__)) #ifndef SOL_TL_GCC_LESS_8_TRIVIALLY_COPY_CONSTRUCTIBLE_MUTEX #define SOL_TL_GCC_LESS_8_TRIVIALLY_COPY_CONSTRUCTIBLE_MUTEX namespace sol { namespace detail { template struct is_trivially_copy_constructible : std::is_trivially_copy_constructible {}; #ifdef _GLIBCXX_VECTOR template struct is_trivially_copy_constructible> : std::is_trivially_copy_constructible {}; #endif }} // namespace sol::detail #endif #define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) sol::detail::is_trivially_copy_constructible::value #define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_ASSIGNABLE(T) std::is_trivially_copy_assignable::value #define SOL_TL_OPTIONAL_IS_TRIVIALLY_DESTRUCTIBLE(T) std::is_trivially_destructible::value #else #define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) std::is_trivially_copy_constructible::value #define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_ASSIGNABLE(T) std::is_trivially_copy_assignable::value #define SOL_TL_OPTIONAL_IS_TRIVIALLY_DESTRUCTIBLE(T) std::is_trivially_destructible::value #endif #if __cplusplus > 201103L #define SOL_TL_OPTIONAL_CXX14 #endif // constexpr implies const in C++11, not C++14 #if (__cplusplus == 201103L || defined(SOL_TL_OPTIONAL_MSVC2015) || defined(SOL_TL_OPTIONAL_GCC49)) /// \exclude #define SOL_TL_OPTIONAL_11_CONSTEXPR #else /// \exclude #define SOL_TL_OPTIONAL_11_CONSTEXPR constexpr #endif namespace sol { #ifndef SOL_TL_MONOSTATE_INPLACE_MUTEX #define SOL_TL_MONOSTATE_INPLACE_MUTEX /// \brief Used to represent an optional with no data; essentially a bool class monostate {}; #endif template class optional; /// \exclude namespace detail { #ifndef SOL_TL_TRAITS_MUTEX #define SOL_TL_TRAITS_MUTEX // C++14-style aliases for brevity template using remove_const_t = typename std::remove_const::type; template using remove_reference_t = typename std::remove_reference::type; template using decay_t = typename std::decay::type; template using enable_if_t = typename std::enable_if::type; template using conditional_t = typename std::conditional::type; // std::conjunction from C++17 template struct conjunction : std::true_type {}; template struct conjunction : B {}; template struct conjunction : std::conditional, B>::type {}; #if defined(_LIBCPP_VERSION) && __cplusplus == 201103L #define SOL_TL_OPTIONAL_LIBCXX_MEM_FN_WORKAROUND #endif // In C++11 mode, there's an issue in libc++'s std::mem_fn // which results in a hard-error when using it in a noexcept expression // in some cases. This is a check to workaround the common failing case. #ifdef SOL_TL_OPTIONAL_LIBCXX_MEM_FN_WORKAROUND template struct is_pointer_to_non_const_member_func : std::false_type {}; template struct is_pointer_to_non_const_member_func : std::true_type {}; template struct is_pointer_to_non_const_member_func : std::true_type {}; template struct is_pointer_to_non_const_member_func : std::true_type {}; template struct is_pointer_to_non_const_member_func : std::true_type {}; template struct is_pointer_to_non_const_member_func : std::true_type {}; template struct is_pointer_to_non_const_member_func : std::true_type {}; template struct is_const_or_const_ref : std::false_type {}; template struct is_const_or_const_ref : std::true_type {}; template struct is_const_or_const_ref : std::true_type {}; #endif // std::invoke from C++17 // https://stackoverflow.com/questions/38288042/c11-14-invoke-workaround template ::value && is_const_or_const_ref::value)>, #endif typename = enable_if_t>::value>, int = 0> constexpr auto invoke(Fn&& f, Args&&... args) noexcept(noexcept(std::mem_fn(f)(std::forward(args)...))) -> decltype(std::mem_fn(f)(std::forward(args)...)) { return std::mem_fn(f)(std::forward(args)...); } template >::value>> constexpr auto invoke(Fn&& f, Args&&... args) noexcept(noexcept(std::forward(f)(std::forward(args)...))) -> decltype(std::forward(f)(std::forward(args)...)) { return std::forward(f)(std::forward(args)...); } // std::invoke_result from C++17 template struct invoke_result_impl; template struct invoke_result_impl(), std::declval()...), void()), Us...> { using type = decltype(detail::invoke(std::declval(), std::declval()...)); }; template using invoke_result = invoke_result_impl; template using invoke_result_t = typename invoke_result::type; #endif // std::void_t from C++17 template struct voider { using type = void; }; template using void_t = typename voider::type; // Trait for checking if a type is a sol::optional template struct is_optional_impl : std::false_type {}; template struct is_optional_impl> : std::true_type {}; template using is_optional = is_optional_impl>; // Change void to sol::monostate template using fixup_void = conditional_t::value, monostate, U>; template > using get_map_return = optional>>; // Check if invoking F for some Us returns void template struct returns_void_impl; template struct returns_void_impl>, U...> : std::is_void> {}; template using returns_void = returns_void_impl; template using enable_if_ret_void = enable_if_t::value>; template using disable_if_ret_void = enable_if_t::value>; template using enable_forward_value = detail::enable_if_t::value && !std::is_same, in_place_t>::value && !std::is_same, detail::decay_t>::value>; template using enable_from_other = detail::enable_if_t::value && !std::is_constructible&>::value && !std::is_constructible&&>::value && !std::is_constructible&>::value && !std::is_constructible&&>::value && !std::is_convertible&, T>::value && !std::is_convertible&&, T>::value && !std::is_convertible&, T>::value && !std::is_convertible&&, T>::value>; template using enable_assign_forward = detail::enable_if_t, detail::decay_t>::value && !detail::conjunction, std::is_same>>::value && std::is_constructible::value && std::is_assignable::value>; template using enable_assign_from_other = detail::enable_if_t::value && std::is_assignable::value && !std::is_constructible&>::value && !std::is_constructible&&>::value && !std::is_constructible&>::value && !std::is_constructible&&>::value && !std::is_convertible&, T>::value && !std::is_convertible&&, T>::value && !std::is_convertible&, T>::value && !std::is_convertible&&, T>::value && !std::is_assignable&>::value && !std::is_assignable&&>::value && !std::is_assignable&>::value && !std::is_assignable&&>::value>; #ifdef _MSC_VER // TODO make a version which works with MSVC template struct is_swappable : std::true_type {}; template struct is_nothrow_swappable : std::true_type {}; #else // https://stackoverflow.com/questions/26744589/what-is-a-proper-way-to-implement-is-swappable-to-test-for-the-swappable-concept namespace swap_adl_tests { // if swap ADL finds this then it would call std::swap otherwise (same // signature) struct tag {}; template tag swap(T&, T&); template tag swap(T (&a)[N], T (&b)[N]); // helper functions to test if an unqualified swap is possible, and if it // becomes std::swap template std::false_type can_swap(...) noexcept(false); template (), std::declval()))> std::true_type can_swap(int) noexcept(noexcept(swap(std::declval(), std::declval()))); template std::false_type uses_std(...); template std::is_same(), std::declval())), tag> uses_std(int); template struct is_std_swap_noexcept : std::integral_constant::value && std::is_nothrow_move_assignable::value> {}; template struct is_std_swap_noexcept : is_std_swap_noexcept {}; template struct is_adl_swap_noexcept : std::integral_constant(0))> {}; } // namespace swap_adl_tests template struct is_swappable : std::integral_constant(0))::value && (!decltype(detail::swap_adl_tests::uses_std(0))::value || (std::is_move_assignable::value && std::is_move_constructible::value))> {}; template struct is_swappable : std::integral_constant(0))::value && (!decltype(detail::swap_adl_tests::uses_std(0))::value || is_swappable::value)> {}; template struct is_nothrow_swappable : std::integral_constant::value && ((decltype(detail::swap_adl_tests::uses_std(0))::value&& detail::swap_adl_tests::is_std_swap_noexcept::value) || (!decltype(detail::swap_adl_tests::uses_std(0))::value&& detail::swap_adl_tests::is_adl_swap_noexcept::value))> {}; #endif // The storage base manages the actual storage, and correctly propagates // trivial destruction from T. This case is for when T is not trivially // destructible. template ::value> struct optional_storage_base { SOL_TL_OPTIONAL_11_CONSTEXPR optional_storage_base() noexcept : m_dummy(), m_has_value(false) { } template SOL_TL_OPTIONAL_11_CONSTEXPR optional_storage_base(in_place_t, U&&... u) : m_value(std::forward(u)...), m_has_value(true) { } ~optional_storage_base() { if (m_has_value) { m_value.~T(); m_has_value = false; } } struct dummy {}; union { dummy m_dummy; T m_value; }; bool m_has_value; }; // This case is for when T is trivially destructible. template struct optional_storage_base { SOL_TL_OPTIONAL_11_CONSTEXPR optional_storage_base() noexcept : m_dummy(), m_has_value(false) { } template SOL_TL_OPTIONAL_11_CONSTEXPR optional_storage_base(in_place_t, U&&... u) : m_value(std::forward(u)...), m_has_value(true) { } // No destructor, so this class is trivially destructible struct dummy {}; union { dummy m_dummy; T m_value; }; bool m_has_value = false; }; // This base class provides some handy member functions which can be used in // further derived classes template struct optional_operations_base : optional_storage_base { using optional_storage_base::optional_storage_base; void hard_reset() noexcept { get().~T(); this->m_has_value = false; } template void construct(Args&&... args) noexcept { new (std::addressof(this->m_value)) T(std::forward(args)...); this->m_has_value = true; } template void assign(Opt&& rhs) { if (this->has_value()) { if (rhs.has_value()) { this->m_value = std::forward(rhs).get(); } else { this->m_value.~T(); this->m_has_value = false; } } else if (rhs.has_value()) { construct(std::forward(rhs).get()); } } bool has_value() const { return this->m_has_value; } SOL_TL_OPTIONAL_11_CONSTEXPR T& get() & { return this->m_value; } SOL_TL_OPTIONAL_11_CONSTEXPR const T& get() const& { return this->m_value; } SOL_TL_OPTIONAL_11_CONSTEXPR T&& get() && { return std::move(this->m_value); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR constexpr const T&& get() const&& { return std::move(this->m_value); } #endif }; // This class manages conditionally having a trivial copy constructor // This specialization is for when T is trivially copy constructible template struct optional_copy_base : optional_operations_base { using optional_operations_base::optional_operations_base; }; // This specialization is for when T is not trivially copy constructible template struct optional_copy_base : optional_operations_base { using base_t = optional_operations_base; using base_t::base_t; optional_copy_base() = default; optional_copy_base(const optional_copy_base& rhs) : base_t() { if (rhs.has_value()) { this->construct(rhs.get()); } else { this->m_has_value = false; } } optional_copy_base(optional_copy_base&& rhs) = default; optional_copy_base& operator=(const optional_copy_base& rhs) = default; optional_copy_base& operator=(optional_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 SOL_TL_OPTIONAL_GCC49 template ::value> struct optional_move_base : optional_copy_base { using optional_copy_base::optional_copy_base; }; #else template struct optional_move_base; #endif template struct optional_move_base : optional_copy_base { using optional_copy_base::optional_copy_base; optional_move_base() = default; optional_move_base(const optional_move_base& rhs) = default; optional_move_base(optional_move_base&& rhs) noexcept(std::is_nothrow_move_constructible::value) { if (rhs.has_value()) { this->construct(std::move(rhs.get())); } else { this->m_has_value = false; } } optional_move_base& operator=(const optional_move_base& rhs) = default; optional_move_base& operator=(optional_move_base&& rhs) = default; }; // This class manages conditionally having a trivial copy assignment operator template struct optional_copy_assign_base : optional_move_base { using optional_move_base::optional_move_base; }; template struct optional_copy_assign_base : optional_move_base { using optional_move_base::optional_move_base; optional_copy_assign_base() = default; optional_copy_assign_base(const optional_copy_assign_base& rhs) = default; optional_copy_assign_base(optional_copy_assign_base&& rhs) = default; optional_copy_assign_base& operator=(const optional_copy_assign_base& rhs) { this->assign(rhs); return *this; } optional_copy_assign_base& operator=(optional_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 SOL_TL_OPTIONAL_GCC49 template ::value&& std::is_trivially_move_constructible::value&& std::is_trivially_move_assignable::value> struct optional_move_assign_base : optional_copy_assign_base { using optional_copy_assign_base::optional_copy_assign_base; }; #else template struct optional_move_assign_base; #endif template struct optional_move_assign_base : optional_copy_assign_base { using optional_copy_assign_base::optional_copy_assign_base; optional_move_assign_base() = default; optional_move_assign_base(const optional_move_assign_base& rhs) = default; optional_move_assign_base(optional_move_assign_base&& rhs) = default; optional_move_assign_base& operator=(const optional_move_assign_base& rhs) = default; optional_move_assign_base& operator=(optional_move_assign_base&& rhs) noexcept( std::is_nothrow_move_constructible::value&& std::is_nothrow_move_assignable::value) { this->assign(std::move(rhs)); return *this; } }; // optional_delete_ctor_base will conditionally delete copy and move // constructors depending on whether T is copy/move constructible template ::value, bool EnableMove = std::is_move_constructible::value> struct optional_delete_ctor_base { optional_delete_ctor_base() = default; optional_delete_ctor_base(const optional_delete_ctor_base&) = default; optional_delete_ctor_base(optional_delete_ctor_base&&) noexcept = default; optional_delete_ctor_base& operator=(const optional_delete_ctor_base&) = default; optional_delete_ctor_base& operator=(optional_delete_ctor_base&&) noexcept = default; }; template struct optional_delete_ctor_base { optional_delete_ctor_base() = default; optional_delete_ctor_base(const optional_delete_ctor_base&) = default; optional_delete_ctor_base(optional_delete_ctor_base&&) noexcept = delete; optional_delete_ctor_base& operator=(const optional_delete_ctor_base&) = default; optional_delete_ctor_base& operator=(optional_delete_ctor_base&&) noexcept = default; }; template struct optional_delete_ctor_base { optional_delete_ctor_base() = default; optional_delete_ctor_base(const optional_delete_ctor_base&) = delete; optional_delete_ctor_base(optional_delete_ctor_base&&) noexcept = default; optional_delete_ctor_base& operator=(const optional_delete_ctor_base&) = default; optional_delete_ctor_base& operator=(optional_delete_ctor_base&&) noexcept = default; }; template struct optional_delete_ctor_base { optional_delete_ctor_base() = default; optional_delete_ctor_base(const optional_delete_ctor_base&) = delete; optional_delete_ctor_base(optional_delete_ctor_base&&) noexcept = delete; optional_delete_ctor_base& operator=(const optional_delete_ctor_base&) = default; optional_delete_ctor_base& operator=(optional_delete_ctor_base&&) noexcept = default; }; // optional_delete_assign_base will conditionally delete copy and move // constructors depending on whether T is copy/move constructible + assignable template ::value && std::is_copy_assignable::value), bool EnableMove = (std::is_move_constructible::value && std::is_move_assignable::value)> struct optional_delete_assign_base { optional_delete_assign_base() = default; optional_delete_assign_base(const optional_delete_assign_base&) = default; optional_delete_assign_base(optional_delete_assign_base&&) noexcept = default; optional_delete_assign_base& operator=(const optional_delete_assign_base&) = default; optional_delete_assign_base& operator=(optional_delete_assign_base&&) noexcept = default; }; template struct optional_delete_assign_base { optional_delete_assign_base() = default; optional_delete_assign_base(const optional_delete_assign_base&) = default; optional_delete_assign_base(optional_delete_assign_base&&) noexcept = default; optional_delete_assign_base& operator=(const optional_delete_assign_base&) = default; optional_delete_assign_base& operator=(optional_delete_assign_base&&) noexcept = delete; }; template struct optional_delete_assign_base { optional_delete_assign_base() = default; optional_delete_assign_base(const optional_delete_assign_base&) = default; optional_delete_assign_base(optional_delete_assign_base&&) noexcept = default; optional_delete_assign_base& operator=(const optional_delete_assign_base&) = delete; optional_delete_assign_base& operator=(optional_delete_assign_base&&) noexcept = default; }; template struct optional_delete_assign_base { optional_delete_assign_base() = default; optional_delete_assign_base(const optional_delete_assign_base&) = default; optional_delete_assign_base(optional_delete_assign_base&&) noexcept = default; optional_delete_assign_base& operator=(const optional_delete_assign_base&) = delete; optional_delete_assign_base& operator=(optional_delete_assign_base&&) noexcept = delete; }; } // namespace detail /// \brief A tag type to represent an empty optional using nullopt_t = std::nullopt_t; /// \brief Represents an empty optional /// \synopsis static constexpr nullopt_t nullopt; /// /// *Examples*: /// ``` /// sol::optional a = sol::nullopt; /// void foo (sol::optional); /// foo(sol::nullopt); //pass an empty optional /// ``` using std::nullopt; class bad_optional_access : public std::exception { public: bad_optional_access() = default; const char* what() const noexcept { return "Optional has no value"; } }; /// An optional object is an object that contains the storage for another /// object and manages the lifetime of this contained object, if any. The /// contained object may be initialized after the optional object has been /// initialized, and may be destroyed before the optional object has been /// destroyed. The initialization state of the contained object is tracked by /// the optional object. template class optional : private detail::optional_move_assign_base, private detail::optional_delete_ctor_base, private detail::optional_delete_assign_base { using base = detail::optional_move_assign_base; static_assert(!std::is_same::value, "instantiation of optional with in_place_t is ill-formed"); static_assert(!std::is_same, nullopt_t>::value, "instantiation of optional with nullopt_t is ill-formed"); public: // The different versions for C++14 and 11 are needed because deduced return // types are not SFINAE-safe. This provides better support for things like // generic lambdas. C.f. // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0826r0.html #if defined(SOL_TL_OPTIONAL_CXX14) && !defined(SOL_TL_OPTIONAL_GCC49) && !defined(SOL_TL_OPTIONAL_GCC54) && !defined(SOL_TL_OPTIONAL_GCC55) /// \group and_then /// Carries out some operation which returns an optional on the stored /// object if there is one. \requires `std::invoke(std::forward(f), /// value())` returns a `std::optional` for some `U`. \returns Let `U` be /// the result of `std::invoke(std::forward(f), value())`. Returns a /// `std::optional`. The return value is empty if `*this` is empty, /// otherwise the return value of `std::invoke(std::forward(f), value())` /// is returned. /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) &; template SOL_TL_OPTIONAL_11_CONSTEXPR auto and_then(F&& f) & { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) &&; template SOL_TL_OPTIONAL_11_CONSTEXPR auto and_then(F&& f) && { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : result(nullopt); } /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) const &; template constexpr auto and_then(F&& f) const& { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) const &&; template constexpr auto and_then(F&& f) const&& { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : result(nullopt); } #endif #else /// \group and_then /// Carries out some operation which returns an optional on the stored /// object if there is one. \requires `std::invoke(std::forward(f), /// value())` returns a `std::optional` for some `U`. /// \returns Let `U` be the result of `std::invoke(std::forward(f), /// value())`. Returns a `std::optional`. The return value is empty if /// `*this` is empty, otherwise the return value of /// `std::invoke(std::forward(f), value())` is returned. /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) &; template SOL_TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t and_then(F&& f) & { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) &&; template SOL_TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t and_then(F&& f) && { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : result(nullopt); } /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) const &; template constexpr detail::invoke_result_t and_then(F&& f) const& { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) const &&; template constexpr detail::invoke_result_t and_then(F&& f) const&& { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : result(nullopt); } #endif #endif #if defined(SOL_TL_OPTIONAL_CXX14) && !defined(SOL_TL_OPTIONAL_GCC49) && !defined(SOL_TL_OPTIONAL_GCC54) && !defined(SOL_TL_OPTIONAL_GCC55) /// \brief Carries out some operation on the stored object if there is one. /// \returns Let `U` be the result of `std::invoke(std::forward(f), /// value())`. Returns a `std::optional`. The return value is empty if /// `*this` is empty, otherwise an `optional` is constructed from the /// return value of `std::invoke(std::forward(f), value())` and is /// returned. /// /// \group map /// \synopsis template constexpr auto map(F &&f) &; template SOL_TL_OPTIONAL_11_CONSTEXPR auto map(F&& f) & { return optional_map_impl(*this, std::forward(f)); } /// \group map /// \synopsis template constexpr auto map(F &&f) &&; template SOL_TL_OPTIONAL_11_CONSTEXPR auto map(F&& f) && { return optional_map_impl(std::move(*this), std::forward(f)); } /// \group map /// \synopsis template constexpr auto map(F &&f) const&; template constexpr auto map(F&& f) const& { return optional_map_impl(*this, std::forward(f)); } /// \group map /// \synopsis template constexpr auto map(F &&f) const&&; template constexpr auto map(F&& f) const&& { return optional_map_impl(std::move(*this), std::forward(f)); } #else /// \brief Carries out some operation on the stored object if there is one. /// \returns Let `U` be the result of `std::invoke(std::forward(f), /// value())`. Returns a `std::optional`. The return value is empty if /// `*this` is empty, otherwise an `optional` is constructed from the /// return value of `std::invoke(std::forward(f), value())` and is /// returned. /// /// \group map /// \synopsis template auto map(F &&f) &; template SOL_TL_OPTIONAL_11_CONSTEXPR decltype(optional_map_impl(std::declval(), std::declval())) map(F&& f) & { return optional_map_impl(*this, std::forward(f)); } /// \group map /// \synopsis template auto map(F &&f) &&; template SOL_TL_OPTIONAL_11_CONSTEXPR decltype(optional_map_impl(std::declval(), std::declval())) map(F&& f) && { return optional_map_impl(std::move(*this), std::forward(f)); } /// \group map /// \synopsis template auto map(F &&f) const&; template constexpr decltype(optional_map_impl(std::declval(), std::declval())) map(F&& f) const& { return optional_map_impl(*this, std::forward(f)); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group map /// \synopsis template auto map(F &&f) const&&; template constexpr decltype(optional_map_impl(std::declval(), std::declval())) map(F&& f) const&& { return optional_map_impl(std::move(*this), std::forward(f)); } #endif #endif /// \brief Calls `f` if the optional is empty /// \requires `std::invoke_result_t` must be void or convertible to /// `optional`. /// \effects If `*this` has a value, returns `*this`. /// Otherwise, if `f` returns `void`, calls `std::forward(f)` and returns /// `std::nullopt`. Otherwise, returns `std::forward(f)()`. /// /// \group or_else /// \synopsis template optional or_else (F &&f) &; template * = nullptr> optional SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) & { if (has_value()) return *this; std::forward(f)(); return nullopt; } /// \exclude template * = nullptr> optional SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) & { return has_value() ? *this : std::forward(f)(); } /// \group or_else /// \synopsis template optional or_else (F &&f) &&; template * = nullptr> optional or_else(F&& f) && { if (has_value()) return std::move(*this); std::forward(f)(); return nullopt; } /// \exclude template * = nullptr> optional SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) && { return has_value() ? std::move(*this) : std::forward(f)(); } /// \group or_else /// \synopsis template optional or_else (F &&f) const &; template * = nullptr> optional or_else(F&& f) const& { if (has_value()) return *this; std::forward(f)(); return nullopt; } /// \exclude template * = nullptr> optional SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) const& { return has_value() ? *this : std::forward(f)(); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \exclude template * = nullptr> optional or_else(F&& f) const&& { if (has_value()) return std::move(*this); std::forward(f)(); return nullopt; } /// \exclude template * = nullptr> optional or_else(F&& f) const&& { return has_value() ? std::move(*this) : std::forward(f)(); } #endif /// \brief Maps the stored value with `f` if there is one, otherwise returns /// `u`. /// /// \details If there is a value stored, then `f` is called with `**this` /// and the value is returned. Otherwise `u` is returned. /// /// \group map_or template U map_or(F&& f, U&& u) & { return has_value() ? detail::invoke(std::forward(f), **this) : std::forward(u); } /// \group map_or template U map_or(F&& f, U&& u) && { return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : std::forward(u); } /// \group map_or template U map_or(F&& f, U&& u) const& { return has_value() ? detail::invoke(std::forward(f), **this) : std::forward(u); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group map_or template U map_or(F&& f, U&& u) const&& { return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : std::forward(u); } #endif /// \brief Maps the stored value with `f` if there is one, otherwise calls /// `u` and returns the result. /// /// \details If there is a value stored, then `f` is /// called with `**this` and the value is returned. Otherwise /// `std::forward(u)()` is returned. /// /// \group map_or_else /// \synopsis template \nauto map_or_else(F &&f, U &&u) &; template detail::invoke_result_t map_or_else(F&& f, U&& u) & { return has_value() ? detail::invoke(std::forward(f), **this) : std::forward(u)(); } /// \group map_or_else /// \synopsis template \nauto map_or_else(F &&f, U &&u) /// &&; template detail::invoke_result_t map_or_else(F&& f, U&& u) && { return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : std::forward(u)(); } /// \group map_or_else /// \synopsis template \nauto map_or_else(F &&f, U &&u) /// const &; template detail::invoke_result_t map_or_else(F&& f, U&& u) const& { return has_value() ? detail::invoke(std::forward(f), **this) : std::forward(u)(); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group map_or_else /// \synopsis template \nauto map_or_else(F &&f, U &&u) /// const &&; template detail::invoke_result_t map_or_else(F&& f, U&& u) const&& { return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : std::forward(u)(); } #endif /// \returns `u` if `*this` has a value, otherwise an empty optional. template constexpr optional::type> conjunction(U&& u) const { using result = optional>; return has_value() ? result { u } : result { nullopt }; } /// \returns `rhs` if `*this` is empty, otherwise the current value. /// \group disjunction SOL_TL_OPTIONAL_11_CONSTEXPR optional disjunction(const optional& rhs) & { return has_value() ? *this : rhs; } /// \group disjunction constexpr optional disjunction(const optional& rhs) const& { return has_value() ? *this : rhs; } /// \group disjunction SOL_TL_OPTIONAL_11_CONSTEXPR optional disjunction(const optional& rhs) && { return has_value() ? std::move(*this) : rhs; } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group disjunction constexpr optional disjunction(const optional& rhs) const&& { return has_value() ? std::move(*this) : rhs; } #endif /// \group disjunction SOL_TL_OPTIONAL_11_CONSTEXPR optional disjunction(optional&& rhs) & { return has_value() ? *this : std::move(rhs); } /// \group disjunction constexpr optional disjunction(optional&& rhs) const& { return has_value() ? *this : std::move(rhs); } /// \group disjunction SOL_TL_OPTIONAL_11_CONSTEXPR optional disjunction(optional&& rhs) && { return has_value() ? std::move(*this) : std::move(rhs); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group disjunction constexpr optional disjunction(optional&& rhs) const&& { return has_value() ? std::move(*this) : std::move(rhs); } #endif /// Takes the value out of the optional, leaving it empty /// \group take optional take() & { optional ret = *this; reset(); return ret; } /// \group take optional take() const& { optional ret = *this; reset(); return ret; } /// \group take optional take() && { optional ret = std::move(*this); reset(); return ret; } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group take optional take() const&& { optional ret = std::move(*this); reset(); return ret; } #endif using value_type = T; /// Constructs an optional that does not contain a value. /// \group ctor_empty constexpr optional() noexcept = default; /// \group ctor_empty constexpr optional(nullopt_t) noexcept { } /// Copy constructor /// /// If `rhs` contains a value, the stored value is direct-initialized with /// it. Otherwise, the constructed optional is empty. SOL_TL_OPTIONAL_11_CONSTEXPR optional(const optional& rhs) = default; /// Move constructor /// /// If `rhs` contains a value, the stored value is direct-initialized with /// it. Otherwise, the constructed optional is empty. SOL_TL_OPTIONAL_11_CONSTEXPR optional(optional&& rhs) = default; /// Constructs the stored value in-place using the given arguments. /// \group in_place /// \synopsis template constexpr explicit optional(in_place_t, Args&&... args); template constexpr explicit optional(detail::enable_if_t::value, in_place_t>, Args&&... args) : base(in_place, std::forward(args)...) { } /// \group in_place /// \synopsis template \nconstexpr explicit optional(in_place_t, std::initializer_list&, Args&&... args); template SOL_TL_OPTIONAL_11_CONSTEXPR explicit optional(detail::enable_if_t&, Args&&...>::value, in_place_t>, std::initializer_list il, Args&&... args) { this->construct(il, std::forward(args)...); } #if 0 // SOL_MODIFICATION /// Constructs the stored value with `u`. /// \synopsis template constexpr optional(U &&u); template ::value>* = nullptr, detail::enable_forward_value* = nullptr> constexpr optional(U&& u) : base(in_place, std::forward(u)) { } /// \exclude template ::value>* = nullptr, detail::enable_forward_value* = nullptr> constexpr explicit optional(U&& u) : base(in_place, std::forward(u)) { } #else /// Constructs the stored value with `u`. /// \synopsis template constexpr optional(U &&u); constexpr optional(T&& u) : base(in_place, std::move(u)) { } /// \exclude constexpr optional(const T& u) : base(in_place, u) { } #endif // sol3 modification /// Converting copy constructor. /// \synopsis template optional(const optional &rhs); template * = nullptr, detail::enable_if_t::value>* = nullptr> optional(const optional& rhs) { if (rhs.has_value()) { this->construct(*rhs); } } /// \exclude template * = nullptr, detail::enable_if_t::value>* = nullptr> explicit optional(const optional& rhs) { if (rhs.has_value()) { this->construct(*rhs); } } /// Converting move constructor. /// \synopsis template optional(optional &&rhs); template * = nullptr, detail::enable_if_t::value>* = nullptr> optional(optional&& rhs) { if (rhs.has_value()) { this->construct(std::move(*rhs)); } } /// \exclude template * = nullptr, detail::enable_if_t::value>* = nullptr> explicit optional(optional&& rhs) { this->construct(std::move(*rhs)); } /// Destroys the stored value if there is one. ~optional() = default; /// Assignment to empty. /// /// Destroys the current value if there is one. optional& operator=(nullopt_t) noexcept { if (has_value()) { this->m_value.~T(); this->m_has_value = false; } return *this; } /// Copy assignment. /// /// Copies the value from `rhs` if there is one. Otherwise resets the stored /// value in `*this`. optional& operator=(const optional& rhs) = default; /// Move assignment. /// /// Moves the value from `rhs` if there is one. Otherwise resets the stored /// value in `*this`. optional& operator=(optional&& rhs) = default; /// Assigns the stored value from `u`, destroying the old value if there was /// one. /// \synopsis optional &operator=(U &&u); template * = nullptr> optional& operator=(U&& u) { if (has_value()) { this->m_value = std::forward(u); } else { this->construct(std::forward(u)); } return *this; } /// Converting copy assignment operator. /// /// Copies the value from `rhs` if there is one. Otherwise resets the stored /// value in `*this`. /// \synopsis optional &operator=(const optional & rhs); template * = nullptr> optional& operator=(const optional& rhs) { if (has_value()) { if (rhs.has_value()) { this->m_value = *rhs; } else { this->hard_reset(); } } if (rhs.has_value()) { this->construct(*rhs); } return *this; } // TODO check exception guarantee /// Converting move assignment operator. /// /// Moves the value from `rhs` if there is one. Otherwise resets the stored /// value in `*this`. /// \synopsis optional &operator=(optional && rhs); template * = nullptr> optional& operator=(optional&& rhs) { if (has_value()) { if (rhs.has_value()) { this->m_value = std::move(*rhs); } else { this->hard_reset(); } } if (rhs.has_value()) { this->construct(std::move(*rhs)); } return *this; } /// Constructs the value in-place, destroying the current one if there is /// one. /// \group emplace template T& emplace(Args&&... args) { static_assert(std::is_constructible::value, "T must be constructible with Args"); *this = nullopt; this->construct(std::forward(args)...); return value(); } /// \group emplace /// \synopsis template \nT& emplace(std::initializer_list il, Args &&... args); template detail::enable_if_t&, Args&&...>::value, T&> emplace(std::initializer_list il, Args&&... args) { *this = nullopt; this->construct(il, std::forward(args)...); return value(); } /// Swaps this optional with the other. /// /// If neither optionals have a value, nothing happens. /// If both have a value, the values are swapped. /// If one has a value, it is moved to the other and the movee is left /// valueless. void swap(optional& rhs) noexcept(std::is_nothrow_move_constructible::value&& detail::is_nothrow_swappable::value) { if (has_value()) { if (rhs.has_value()) { using std::swap; swap(**this, *rhs); } else { new (std::addressof(rhs.m_value)) T(std::move(this->m_value)); this->m_value.T::~T(); } } else if (rhs.has_value()) { new (std::addressof(this->m_value)) T(std::move(rhs.m_value)); rhs.m_value.T::~T(); } } /// \returns a pointer to the stored value /// \requires a value is stored /// \group pointer /// \synopsis constexpr const T *operator->() const; constexpr const T* operator->() const { return std::addressof(this->m_value); } /// \group pointer /// \synopsis constexpr T *operator->(); SOL_TL_OPTIONAL_11_CONSTEXPR T* operator->() { return std::addressof(this->m_value); } /// \returns the stored value /// \requires a value is stored /// \group deref /// \synopsis constexpr T &operator*(); SOL_TL_OPTIONAL_11_CONSTEXPR T& operator*() & { return this->m_value; } /// \group deref /// \synopsis constexpr const T &operator*() const; constexpr const T& operator*() const& { return this->m_value; } /// \exclude SOL_TL_OPTIONAL_11_CONSTEXPR T&& operator*() && { return std::move(this->m_value); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \exclude constexpr const T&& operator*() const&& { return std::move(this->m_value); } #endif /// \returns whether or not the optional has a value /// \group has_value constexpr bool has_value() const noexcept { return this->m_has_value; } /// \group has_value constexpr explicit operator bool() const noexcept { return this->m_has_value; } /// \returns the contained value if there is one, otherwise throws /// [bad_optional_access] /// \group value /// \synopsis constexpr T &value(); SOL_TL_OPTIONAL_11_CONSTEXPR T& value() & { if (has_value()) return this->m_value; #if defined(SOL_NO_EXCEPTIONS) && SOL_NO_EXCEPTIONS != 0 std::abort(); #else throw bad_optional_access(); #endif // No exceptions allowed } /// \group value /// \synopsis constexpr const T &value() const; SOL_TL_OPTIONAL_11_CONSTEXPR const T& value() const& { if (has_value()) return this->m_value; #if defined(SOL_NO_EXCEPTIONS) && SOL_NO_EXCEPTIONS != 0 std::abort(); #else throw bad_optional_access(); #endif // No exceptions allowed } /// \exclude SOL_TL_OPTIONAL_11_CONSTEXPR T&& value() && { if (has_value()) return std::move(this->m_value); #if defined(SOL_NO_EXCEPTIONS) && SOL_NO_EXCEPTIONS != 0 std::abort(); #else throw bad_optional_access(); #endif // No exceptions allowed } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \exclude SOL_TL_OPTIONAL_11_CONSTEXPR const T&& value() const&& { if (has_value()) return std::move(this->m_value); #if defined(SOL_NO_EXCEPTIONS) && SOL_NO_EXCEPTIONS != 0 std::abort(); #else throw bad_optional_access(); #endif // No exceptions allowed } #endif /// \returns the stored value if there is one, otherwise returns `u` /// \group value_or template constexpr T value_or(U&& u) const& { static_assert(std::is_copy_constructible::value && std::is_convertible::value, "T must be copy constructible and convertible from U"); return has_value() ? **this : static_cast(std::forward(u)); } /// \group value_or template SOL_TL_OPTIONAL_11_CONSTEXPR T value_or(U&& u) && { static_assert(std::is_move_constructible::value && std::is_convertible::value, "T must be move constructible and convertible from U"); return has_value() ? **this : static_cast(std::forward(u)); } /// Destroys the stored value if one exists, making the optional empty void reset() noexcept { if (has_value()) { this->m_value.~T(); this->m_has_value = false; } } }; // namespace sol /// \group relop /// \brief Compares two optional objects /// \details If both optionals contain a value, they are compared with `T`s /// relational operators. Otherwise `lhs` and `rhs` are equal only if they are /// both empty, and `lhs` is less than `rhs` only if `rhs` is empty and `lhs` /// is not. template inline constexpr bool operator==(const optional& lhs, const optional& rhs) { return lhs.has_value() == rhs.has_value() && (!lhs.has_value() || *lhs == *rhs); } /// \group relop template inline constexpr bool operator!=(const optional& lhs, const optional& rhs) { return lhs.has_value() != rhs.has_value() || (lhs.has_value() && *lhs != *rhs); } /// \group relop template inline constexpr bool operator<(const optional& lhs, const optional& rhs) { return rhs.has_value() && (!lhs.has_value() || *lhs < *rhs); } /// \group relop template inline constexpr bool operator>(const optional& lhs, const optional& rhs) { return lhs.has_value() && (!rhs.has_value() || *lhs > *rhs); } /// \group relop template inline constexpr bool operator<=(const optional& lhs, const optional& rhs) { return !lhs.has_value() || (rhs.has_value() && *lhs <= *rhs); } /// \group relop template inline constexpr bool operator>=(const optional& lhs, const optional& rhs) { return !rhs.has_value() || (lhs.has_value() && *lhs >= *rhs); } /// \group relop_nullopt /// \brief Compares an optional to a `nullopt` /// \details Equivalent to comparing the optional to an empty optional template inline constexpr bool operator==(const optional& lhs, nullopt_t) noexcept { return !lhs.has_value(); } /// \group relop_nullopt template inline constexpr bool operator==(nullopt_t, const optional& rhs) noexcept { return !rhs.has_value(); } /// \group relop_nullopt template inline constexpr bool operator!=(const optional& lhs, nullopt_t) noexcept { return lhs.has_value(); } /// \group relop_nullopt template inline constexpr bool operator!=(nullopt_t, const optional& rhs) noexcept { return rhs.has_value(); } /// \group relop_nullopt template inline constexpr bool operator<(const optional&, nullopt_t) noexcept { return false; } /// \group relop_nullopt template inline constexpr bool operator<(nullopt_t, const optional& rhs) noexcept { return rhs.has_value(); } /// \group relop_nullopt template inline constexpr bool operator<=(const optional& lhs, nullopt_t) noexcept { return !lhs.has_value(); } /// \group relop_nullopt template inline constexpr bool operator<=(nullopt_t, const optional&) noexcept { return true; } /// \group relop_nullopt template inline constexpr bool operator>(const optional& lhs, nullopt_t) noexcept { return lhs.has_value(); } /// \group relop_nullopt template inline constexpr bool operator>(nullopt_t, const optional&) noexcept { return false; } /// \group relop_nullopt template inline constexpr bool operator>=(const optional&, nullopt_t) noexcept { return true; } /// \group relop_nullopt template inline constexpr bool operator>=(nullopt_t, const optional& rhs) noexcept { return !rhs.has_value(); } /// \group relop_t /// \brief Compares the optional with a value. /// \details If the optional has a value, it is compared with the other value /// using `T`s relational operators. Otherwise, the optional is considered /// less than the value. template inline constexpr bool operator==(const optional& lhs, const U& rhs) { return lhs.has_value() ? *lhs == rhs : false; } /// \group relop_t template inline constexpr bool operator==(const U& lhs, const optional& rhs) { return rhs.has_value() ? lhs == *rhs : false; } /// \group relop_t template inline constexpr bool operator!=(const optional& lhs, const U& rhs) { return lhs.has_value() ? *lhs != rhs : true; } /// \group relop_t template inline constexpr bool operator!=(const U& lhs, const optional& rhs) { return rhs.has_value() ? lhs != *rhs : true; } /// \group relop_t template inline constexpr bool operator<(const optional& lhs, const U& rhs) { return lhs.has_value() ? *lhs < rhs : true; } /// \group relop_t template inline constexpr bool operator<(const U& lhs, const optional& rhs) { return rhs.has_value() ? lhs < *rhs : false; } /// \group relop_t template inline constexpr bool operator<=(const optional& lhs, const U& rhs) { return lhs.has_value() ? *lhs <= rhs : true; } /// \group relop_t template inline constexpr bool operator<=(const U& lhs, const optional& rhs) { return rhs.has_value() ? lhs <= *rhs : false; } /// \group relop_t template inline constexpr bool operator>(const optional& lhs, const U& rhs) { return lhs.has_value() ? *lhs > rhs : false; } /// \group relop_t template inline constexpr bool operator>(const U& lhs, const optional& rhs) { return rhs.has_value() ? lhs > *rhs : true; } /// \group relop_t template inline constexpr bool operator>=(const optional& lhs, const U& rhs) { return lhs.has_value() ? *lhs >= rhs : false; } /// \group relop_t template inline constexpr bool operator>=(const U& lhs, const optional& rhs) { return rhs.has_value() ? lhs >= *rhs : true; } /// \synopsis template \nvoid swap(optional &lhs, optional &rhs); template ::value>* = nullptr, detail::enable_if_t::value>* = nullptr> void swap(optional& lhs, optional& rhs) noexcept(noexcept(lhs.swap(rhs))) { return lhs.swap(rhs); } namespace detail { struct i_am_secret {}; } // namespace detail template ::value, detail::decay_t, T>> inline constexpr optional make_optional(U&& v) { return optional(std::forward(v)); } template inline constexpr optional make_optional(Args&&... args) { return optional(in_place, std::forward(args)...); } template inline constexpr optional make_optional(std::initializer_list il, Args&&... args) { return optional(in_place, il, std::forward(args)...); } #if __cplusplus >= 201703L template optional(T)->optional; #endif /// \exclude namespace detail { #ifdef SOL_TL_OPTIONAL_CXX14 template (), *std::declval())), detail::enable_if_t::value>* = nullptr> constexpr auto optional_map_impl(Opt&& opt, F&& f) { return opt.has_value() ? detail::invoke(std::forward(f), *std::forward(opt)) : optional(nullopt); } template (), *std::declval())), detail::enable_if_t::value>* = nullptr> auto optional_map_impl(Opt&& opt, F&& f) { if (opt.has_value()) { detail::invoke(std::forward(f), *std::forward(opt)); return make_optional(monostate {}); } return optional(nullopt); } #else template (), *std::declval())), detail::enable_if_t::value>* = nullptr> constexpr auto optional_map_impl(Opt&& opt, F&& f) -> optional { return opt.has_value() ? detail::invoke(std::forward(f), *std::forward(opt)) : optional(nullopt); } template (), *std::declval())), detail::enable_if_t::value>* = nullptr> auto optional_map_impl(Opt&& opt, F&& f) -> optional { if (opt.has_value()) { detail::invoke(std::forward(f), *std::forward(opt)); return monostate {}; } return nullopt; } #endif } // namespace detail /// Specialization for when `T` is a reference. `optional` acts similarly /// to a `T*`, but provides more operations and shows intent more clearly. /// /// *Examples*: /// /// ``` /// int i = 42; /// sol::optional o = i; /// *o == 42; //true /// i = 12; /// *o = 12; //true /// &*o == &i; //true /// ``` /// /// Assignment has rebind semantics rather than assign-through semantics: /// /// ``` /// int j = 8; /// o = j; /// /// &*o == &j; //true /// ``` template class optional { public: // The different versions for C++14 and 11 are needed because deduced return // types are not SFINAE-safe. This provides better support for things like // generic lambdas. C.f. // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0826r0.html #if defined(SOL_TL_OPTIONAL_CXX14) && !defined(SOL_TL_OPTIONAL_GCC49) && !defined(SOL_TL_OPTIONAL_GCC54) && !defined(SOL_TL_OPTIONAL_GCC55) /// \group and_then /// Carries out some operation which returns an optional on the stored /// object if there is one. \requires `std::invoke(std::forward(f), /// value())` returns a `std::optional` for some `U`. \returns Let `U` be /// the result of `std::invoke(std::forward(f), value())`. Returns a /// `std::optional`. The return value is empty if `*this` is empty, /// otherwise the return value of `std::invoke(std::forward(f), value())` /// is returned. /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) &; template SOL_TL_OPTIONAL_11_CONSTEXPR auto and_then(F&& f) & { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) &&; template SOL_TL_OPTIONAL_11_CONSTEXPR auto and_then(F&& f) && { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) const &; template constexpr auto and_then(F&& f) const& { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) const &&; template constexpr auto and_then(F&& f) const&& { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } #endif #else /// \group and_then /// Carries out some operation which returns an optional on the stored /// object if there is one. \requires `std::invoke(std::forward(f), /// value())` returns a `std::optional` for some `U`. \returns Let `U` be /// the result of `std::invoke(std::forward(f), value())`. Returns a /// `std::optional`. The return value is empty if `*this` is empty, /// otherwise the return value of `std::invoke(std::forward(f), value())` /// is returned. /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) &; template SOL_TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t and_then(F&& f) & { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) &&; template SOL_TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t and_then(F&& f) && { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) const &; template constexpr detail::invoke_result_t and_then(F&& f) const& { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group and_then /// \synopsis template \nconstexpr auto and_then(F &&f) const &&; template constexpr detail::invoke_result_t and_then(F&& f) const&& { using result = detail::invoke_result_t; static_assert(detail::is_optional::value, "F must return an optional"); return has_value() ? detail::invoke(std::forward(f), **this) : result(nullopt); } #endif #endif #if defined(SOL_TL_OPTIONAL_CXX14) && !defined(SOL_TL_OPTIONAL_GCC49) && !defined(SOL_TL_OPTIONAL_GCC54) && !defined(SOL_TL_OPTIONAL_GCC55) /// \brief Carries out some operation on the stored object if there is one. /// \returns Let `U` be the result of `std::invoke(std::forward(f), /// value())`. Returns a `std::optional`. The return value is empty if /// `*this` is empty, otherwise an `optional` is constructed from the /// return value of `std::invoke(std::forward(f), value())` and is /// returned. /// /// \group map /// \synopsis template constexpr auto map(F &&f) &; template SOL_TL_OPTIONAL_11_CONSTEXPR auto map(F&& f) & { return detail::optional_map_impl(*this, std::forward(f)); } /// \group map /// \synopsis template constexpr auto map(F &&f) &&; template SOL_TL_OPTIONAL_11_CONSTEXPR auto map(F&& f) && { return detail::optional_map_impl(std::move(*this), std::forward(f)); } /// \group map /// \synopsis template constexpr auto map(F &&f) const&; template constexpr auto map(F&& f) const& { return detail::optional_map_impl(*this, std::forward(f)); } /// \group map /// \synopsis template constexpr auto map(F &&f) const&&; template constexpr auto map(F&& f) const&& { return detail::optional_map_impl(std::move(*this), std::forward(f)); } #else /// \brief Carries out some operation on the stored object if there is one. /// \returns Let `U` be the result of `std::invoke(std::forward(f), /// value())`. Returns a `std::optional`. The return value is empty if /// `*this` is empty, otherwise an `optional` is constructed from the /// return value of `std::invoke(std::forward(f), value())` and is /// returned. /// /// \group map /// \synopsis template auto map(F &&f) &; template SOL_TL_OPTIONAL_11_CONSTEXPR decltype(detail::optional_map_impl(std::declval(), std::declval())) map(F&& f) & { return detail::optional_map_impl(*this, std::forward(f)); } /// \group map /// \synopsis template auto map(F &&f) &&; template SOL_TL_OPTIONAL_11_CONSTEXPR decltype(detail::optional_map_impl(std::declval(), std::declval())) map(F&& f) && { return detail::optional_map_impl(std::move(*this), std::forward(f)); } /// \group map /// \synopsis template auto map(F &&f) const&; template constexpr decltype(detail::optional_map_impl(std::declval(), std::declval())) map(F&& f) const& { return detail::optional_map_impl(*this, std::forward(f)); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group map /// \synopsis template auto map(F &&f) const&&; template constexpr decltype(detail::optional_map_impl(std::declval(), std::declval())) map(F&& f) const&& { return detail::optional_map_impl(std::move(*this), std::forward(f)); } #endif #endif /// \brief Calls `f` if the optional is empty /// \requires `std::invoke_result_t` must be void or convertible to /// `optional`. \effects If `*this` has a value, returns `*this`. /// Otherwise, if `f` returns `void`, calls `std::forward(f)` and returns /// `std::nullopt`. Otherwise, returns `std::forward(f)()`. /// /// \group or_else /// \synopsis template optional or_else (F &&f) &; template * = nullptr> optional SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) & { if (has_value()) return *this; std::forward(f)(); return nullopt; } /// \exclude template * = nullptr> optional SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) & { return has_value() ? *this : std::forward(f)(); } /// \group or_else /// \synopsis template optional or_else (F &&f) &&; template * = nullptr> optional or_else(F&& f) && { if (has_value()) return std::move(*this); std::forward(f)(); return nullopt; } /// \exclude template * = nullptr> optional SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) && { return has_value() ? std::move(*this) : std::forward(f)(); } /// \group or_else /// \synopsis template optional or_else (F &&f) const &; template * = nullptr> optional or_else(F&& f) const& { if (has_value()) return *this; std::forward(f)(); return nullopt; } /// \exclude template * = nullptr> optional SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) const& { return has_value() ? *this : std::forward(f)(); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \exclude template * = nullptr> optional or_else(F&& f) const&& { if (has_value()) return std::move(*this); std::forward(f)(); return nullopt; } /// \exclude template * = nullptr> optional or_else(F&& f) const&& { return has_value() ? std::move(*this) : std::forward(f)(); } #endif /// \brief Maps the stored value with `f` if there is one, otherwise returns /// `u`. /// /// \details If there is a value stored, then `f` is called with `**this` /// and the value is returned. Otherwise `u` is returned. /// /// \group map_or template U map_or(F&& f, U&& u) & { return has_value() ? detail::invoke(std::forward(f), **this) : std::forward(u); } /// \group map_or template U map_or(F&& f, U&& u) && { return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : std::forward(u); } /// \group map_or template U map_or(F&& f, U&& u) const& { return has_value() ? detail::invoke(std::forward(f), **this) : std::forward(u); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group map_or template U map_or(F&& f, U&& u) const&& { return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : std::forward(u); } #endif /// \brief Maps the stored value with `f` if there is one, otherwise calls /// `u` and returns the result. /// /// \details If there is a value stored, then `f` is /// called with `**this` and the value is returned. Otherwise /// `std::forward(u)()` is returned. /// /// \group map_or_else /// \synopsis template \nauto map_or_else(F &&f, U &&u) &; template detail::invoke_result_t map_or_else(F&& f, U&& u) & { return has_value() ? detail::invoke(std::forward(f), **this) : std::forward(u)(); } /// \group map_or_else /// \synopsis template \nauto map_or_else(F &&f, U &&u) /// &&; template detail::invoke_result_t map_or_else(F&& f, U&& u) && { return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : std::forward(u)(); } /// \group map_or_else /// \synopsis template \nauto map_or_else(F &&f, U &&u) /// const &; template detail::invoke_result_t map_or_else(F&& f, U&& u) const& { return has_value() ? detail::invoke(std::forward(f), **this) : std::forward(u)(); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group map_or_else /// \synopsis template \nauto map_or_else(F &&f, U &&u) /// const &&; template detail::invoke_result_t map_or_else(F&& f, U&& u) const&& { return has_value() ? detail::invoke(std::forward(f), std::move(**this)) : std::forward(u)(); } #endif /// \returns `u` if `*this` has a value, otherwise an empty optional. template constexpr optional::type> conjunction(U&& u) const { using result = optional>; return has_value() ? result { u } : result { nullopt }; } /// \returns `rhs` if `*this` is empty, otherwise the current value. /// \group disjunction SOL_TL_OPTIONAL_11_CONSTEXPR optional disjunction(const optional& rhs) & { return has_value() ? *this : rhs; } /// \group disjunction constexpr optional disjunction(const optional& rhs) const& { return has_value() ? *this : rhs; } /// \group disjunction SOL_TL_OPTIONAL_11_CONSTEXPR optional disjunction(const optional& rhs) && { return has_value() ? std::move(*this) : rhs; } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group disjunction constexpr optional disjunction(const optional& rhs) const&& { return has_value() ? std::move(*this) : rhs; } #endif /// \group disjunction SOL_TL_OPTIONAL_11_CONSTEXPR optional disjunction(optional&& rhs) & { return has_value() ? *this : std::move(rhs); } /// \group disjunction constexpr optional disjunction(optional&& rhs) const& { return has_value() ? *this : std::move(rhs); } /// \group disjunction SOL_TL_OPTIONAL_11_CONSTEXPR optional disjunction(optional&& rhs) && { return has_value() ? std::move(*this) : std::move(rhs); } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group disjunction constexpr optional disjunction(optional&& rhs) const&& { return has_value() ? std::move(*this) : std::move(rhs); } #endif /// Takes the value out of the optional, leaving it empty /// \group take optional take() & { optional ret = *this; reset(); return ret; } /// \group take optional take() const& { optional ret = *this; reset(); return ret; } /// \group take optional take() && { optional ret = std::move(*this); reset(); return ret; } #ifndef SOL_TL_OPTIONAL_NO_CONSTRR /// \group take optional take() const&& { optional ret = std::move(*this); reset(); return ret; } #endif using value_type = T&; /// Constructs an optional that does not contain a value. /// \group ctor_empty constexpr optional() noexcept : m_value(nullptr) { } /// \group ctor_empty constexpr optional(nullopt_t) noexcept : m_value(nullptr) { } /// Copy constructor /// /// If `rhs` contains a value, the stored value is direct-initialized with /// it. Otherwise, the constructed optional is empty. SOL_TL_OPTIONAL_11_CONSTEXPR optional(const optional& rhs) noexcept = default; /// Move constructor /// /// If `rhs` contains a value, the stored value is direct-initialized with /// it. Otherwise, the constructed optional is empty. SOL_TL_OPTIONAL_11_CONSTEXPR optional(optional&& rhs) = default; /// Constructs the stored value with `u`. /// \synopsis template constexpr optional(U &&u); template >::value>* = nullptr> constexpr optional(U&& u) : m_value(std::addressof(u)) { static_assert(std::is_lvalue_reference::value, "U must be an lvalue"); } /// \exclude template constexpr explicit optional(const optional& rhs) : optional(*rhs) { } /// No-op ~optional() = default; /// Assignment to empty. /// /// Destroys the current value if there is one. optional& operator=(nullopt_t) noexcept { m_value = nullptr; return *this; } /// Copy assignment. /// /// Rebinds this optional to the referee of `rhs` if there is one. Otherwise /// resets the stored value in `*this`. optional& operator=(const optional& rhs) = default; /// Rebinds this optional to `u`. /// /// \requires `U` must be an lvalue reference. /// \synopsis optional &operator=(U &&u); template >::value>* = nullptr> optional& operator=(U&& u) { static_assert(std::is_lvalue_reference::value, "U must be an lvalue"); m_value = std::addressof(u); return *this; } /// Converting copy assignment operator. /// /// Rebinds this optional to the referee of `rhs` if there is one. Otherwise /// resets the stored value in `*this`. template optional& operator=(const optional& rhs) { m_value = std::addressof(rhs.value()); return *this; } /// Constructs the value in-place, destroying the current one if there is /// one. /// /// \group emplace template T& emplace(Args&&... args) noexcept { static_assert(std::is_constructible::value, "T must be constructible with Args"); *this = nullopt; this->construct(std::forward(args)...); } /// Swaps this optional with the other. /// /// If neither optionals have a value, nothing happens. /// If both have a value, the values are swapped. /// If one has a value, it is moved to the other and the movee is left /// valueless. void swap(optional& rhs) noexcept { std::swap(m_value, rhs.m_value); } /// \returns a pointer to the stored value /// \requires a value is stored /// \group pointer /// \synopsis constexpr const T *operator->() const; constexpr const T* operator->() const { return m_value; } /// \group pointer /// \synopsis constexpr T *operator->(); SOL_TL_OPTIONAL_11_CONSTEXPR T* operator->() { return m_value; } /// \returns the stored value /// \requires a value is stored /// \group deref /// \synopsis constexpr T &operator*(); SOL_TL_OPTIONAL_11_CONSTEXPR T& operator*() { return *m_value; } /// \group deref /// \synopsis constexpr const T &operator*() const; constexpr const T& operator*() const { return *m_value; } /// \returns whether or not the optional has a value /// \group has_value constexpr bool has_value() const noexcept { return m_value != nullptr; } /// \group has_value constexpr explicit operator bool() const noexcept { return m_value != nullptr; } /// \returns the contained value if there is one, otherwise throws /// [bad_optional_access] /// \group value /// synopsis constexpr T &value(); SOL_TL_OPTIONAL_11_CONSTEXPR T& value() { if (has_value()) return *m_value; #if defined(SOL_NO_EXCEPTIONS) && SOL_NO_EXCEPTIONS != 0 std::abort(); #else throw bad_optional_access(); #endif // No exceptions allowed } /// \group value /// \synopsis constexpr const T &value() const; SOL_TL_OPTIONAL_11_CONSTEXPR const T& value() const { if (has_value()) return *m_value; #if defined(SOL_NO_EXCEPTIONS) && SOL_NO_EXCEPTIONS != 0 std::abort(); #else throw bad_optional_access(); #endif // No exceptions allowed } /// \returns the stored value if there is one, otherwise returns `u` /// \group value_or template constexpr T& value_or(U&& u) const { static_assert(std::is_convertible::value, "T must be convertible from U"); return has_value() ? const_cast(**this) : static_cast(std::forward(u)); } /// Destroys the stored value if one exists, making the optional empty void reset() noexcept { m_value = nullptr; } private: T* m_value; }; } // namespace sol namespace std { // TODO SFINAE template struct hash<::sol::optional> { ::std::size_t operator()(const ::sol::optional& o) const { if (!o.has_value()) return 0; return ::std::hash<::sol::detail::remove_const_t>()(*o); } }; } // namespace std #endif // SOL_TL_OPTIONAL_HPP