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sol2/include/sol/optional_implementation.hpp
ThePhD c1a8cb1dc5
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2019-03-13 05:18:06 -04:00

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// 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
// <http://creativecommons.org/publicdomain/zero/1.0/>.
///
#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 <exception>
#include <functional>
#include <new>
#include <type_traits>
#include <utility>
#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<T>::value
#define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_ASSIGNABLE(T) std::has_trivial_copy_assign<T>::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<T>::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 <class T>
struct is_trivially_copy_constructible : std::is_trivially_copy_constructible<T> {};
#ifdef _GLIBCXX_VECTOR
template <class T, class A>
struct is_trivially_copy_constructible<std::vector<T, A>> : std::is_trivially_copy_constructible<T> {};
#endif
}} // namespace sol::detail
#endif
#define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) sol::detail::is_trivially_copy_constructible<T>::value
#define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_ASSIGNABLE(T) std::is_trivially_copy_assignable<T>::value
#define SOL_TL_OPTIONAL_IS_TRIVIALLY_DESTRUCTIBLE(T) std::is_trivially_destructible<T>::value
#else
#define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) std::is_trivially_copy_constructible<T>::value
#define SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_ASSIGNABLE(T) std::is_trivially_copy_assignable<T>::value
#define SOL_TL_OPTIONAL_IS_TRIVIALLY_DESTRUCTIBLE(T) std::is_trivially_destructible<T>::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 T>
class optional;
/// \exclude
namespace detail {
#ifndef SOL_TL_TRAITS_MUTEX
#define SOL_TL_TRAITS_MUTEX
// C++14-style aliases for brevity
template <class T>
using remove_const_t = typename std::remove_const<T>::type;
template <class T>
using remove_reference_t = typename std::remove_reference<T>::type;
template <class T>
using decay_t = typename std::decay<T>::type;
template <bool E, class T = void>
using enable_if_t = typename std::enable_if<E, T>::type;
template <bool B, class T, class F>
using conditional_t = typename std::conditional<B, T, F>::type;
// std::conjunction from C++17
template <class...>
struct conjunction : std::true_type {};
template <class B>
struct conjunction<B> : B {};
template <class B, class... Bs>
struct conjunction<B, Bs...> : std::conditional<bool(B::value), conjunction<Bs...>, B>::type {};
#if defined(_LIBCPP_VERSION) && __cplusplus == 201103L
#define 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 <class T>
struct is_pointer_to_non_const_member_func : std::false_type {};
template <class T, class Ret, class... Args>
struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...)> : std::true_type {};
template <class T, class Ret, class... Args>
struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...)&> : std::true_type {};
template <class T, class Ret, class... Args>
struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...) &&> : std::true_type {};
template <class T, class Ret, class... Args>
struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...) volatile> : std::true_type {};
template <class T, class Ret, class... Args>
struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...) volatile&> : std::true_type {};
template <class T, class Ret, class... Args>
struct is_pointer_to_non_const_member_func<Ret (T::*)(Args...) volatile&&> : std::true_type {};
template <class T>
struct is_const_or_const_ref : std::false_type {};
template <class T>
struct is_const_or_const_ref<T const&> : std::true_type {};
template <class T>
struct is_const_or_const_ref<T const> : std::true_type {};
#endif
// std::invoke from C++17
// https://stackoverflow.com/questions/38288042/c11-14-invoke-workaround
template <typename Fn, typename... Args,
#ifdef SOL_TL_OPTIONAL_LIBCXX_MEM_FN_WORKAROUND
typename = enable_if_t<!(is_pointer_to_non_const_member_func<Fn>::value && is_const_or_const_ref<Args...>::value)>,
#endif
typename = enable_if_t<std::is_member_pointer<decay_t<Fn>>::value>, int = 0>
constexpr auto invoke(Fn&& f, Args&&... args) noexcept(noexcept(std::mem_fn(f)(std::forward<Args>(args)...)))
-> decltype(std::mem_fn(f)(std::forward<Args>(args)...)) {
return std::mem_fn(f)(std::forward<Args>(args)...);
}
template <typename Fn, typename... Args, typename = enable_if_t<!std::is_member_pointer<decay_t<Fn>>::value>>
constexpr auto invoke(Fn&& f, Args&&... args) noexcept(noexcept(std::forward<Fn>(f)(std::forward<Args>(args)...)))
-> decltype(std::forward<Fn>(f)(std::forward<Args>(args)...)) {
return std::forward<Fn>(f)(std::forward<Args>(args)...);
}
// std::invoke_result from C++17
template <class F, class, class... Us>
struct invoke_result_impl;
template <class F, class... Us>
struct invoke_result_impl<F, decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...), void()), Us...> {
using type = decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...));
};
template <class F, class... Us>
using invoke_result = invoke_result_impl<F, void, Us...>;
template <class F, class... Us>
using invoke_result_t = typename invoke_result<F, Us...>::type;
#endif
// std::void_t from C++17
template <class...>
struct voider {
using type = void;
};
template <class... Ts>
using void_t = typename voider<Ts...>::type;
// Trait for checking if a type is a sol::optional
template <class T>
struct is_optional_impl : std::false_type {};
template <class T>
struct is_optional_impl<optional<T>> : std::true_type {};
template <class T>
using is_optional = is_optional_impl<decay_t<T>>;
// Change void to sol::monostate
template <class U>
using fixup_void = conditional_t<std::is_void<U>::value, monostate, U>;
template <class F, class U, class = invoke_result_t<F, U>>
using get_map_return = optional<fixup_void<invoke_result_t<F, U>>>;
// Check if invoking F for some Us returns void
template <class F, class = void, class... U>
struct returns_void_impl;
template <class F, class... U>
struct returns_void_impl<F, void_t<invoke_result_t<F, U...>>, U...> : std::is_void<invoke_result_t<F, U...>> {};
template <class F, class... U>
using returns_void = returns_void_impl<F, void, U...>;
template <class T, class... U>
using enable_if_ret_void = enable_if_t<returns_void<T&&, U...>::value>;
template <class T, class... U>
using disable_if_ret_void = enable_if_t<!returns_void<T&&, U...>::value>;
template <class T, class U>
using enable_forward_value = detail::enable_if_t<std::is_constructible<T, U&&>::value && !std::is_same<detail::decay_t<U>, in_place_t>::value
&& !std::is_same<optional<T>, detail::decay_t<U>>::value>;
template <class T, class U, class Other>
using enable_from_other = detail::enable_if_t<std::is_constructible<T, Other>::value && !std::is_constructible<T, optional<U>&>::value
&& !std::is_constructible<T, optional<U>&&>::value && !std::is_constructible<T, const optional<U>&>::value
&& !std::is_constructible<T, const optional<U>&&>::value && !std::is_convertible<optional<U>&, T>::value
&& !std::is_convertible<optional<U>&&, T>::value && !std::is_convertible<const optional<U>&, T>::value
&& !std::is_convertible<const optional<U>&&, T>::value>;
template <class T, class U>
using enable_assign_forward = detail::enable_if_t<!std::is_same<optional<T>, 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<T&, U>::value>;
template <class T, class U, class Other>
using enable_assign_from_other = detail::enable_if_t<std::is_constructible<T, Other>::value && std::is_assignable<T&, Other>::value
&& !std::is_constructible<T, optional<U>&>::value && !std::is_constructible<T, optional<U>&&>::value
&& !std::is_constructible<T, const optional<U>&>::value && !std::is_constructible<T, const optional<U>&&>::value
&& !std::is_convertible<optional<U>&, T>::value && !std::is_convertible<optional<U>&&, T>::value
&& !std::is_convertible<const optional<U>&, T>::value && !std::is_convertible<const optional<U>&&, T>::value
&& !std::is_assignable<T&, optional<U>&>::value && !std::is_assignable<T&, optional<U>&&>::value
&& !std::is_assignable<T&, const optional<U>&>::value && !std::is_assignable<T&, const optional<U>&&>::value>;
#ifdef _MSC_VER
// TODO make a version which works with MSVC
template <class T, class U = T>
struct is_swappable : std::true_type {};
template <class T, class U = T>
struct is_nothrow_swappable : std::true_type {};
#else
// https://stackoverflow.com/questions/26744589/what-is-a-proper-way-to-implement-is-swappable-to-test-for-the-swappable-concept
namespace swap_adl_tests {
// if swap ADL finds this then it would call std::swap otherwise (same
// signature)
struct tag {};
template <class T>
tag swap(T&, T&);
template <class T, std::size_t N>
tag swap(T (&a)[N], T (&b)[N]);
// helper functions to test if an unqualified swap is possible, and if it
// becomes std::swap
template <class, class>
std::false_type can_swap(...) noexcept(false);
template <class T, class U, class = decltype(swap(std::declval<T&>(), std::declval<U&>()))>
std::true_type can_swap(int) noexcept(noexcept(swap(std::declval<T&>(), std::declval<U&>())));
template <class, class>
std::false_type uses_std(...);
template <class T, class U>
std::is_same<decltype(swap(std::declval<T&>(), std::declval<U&>())), tag> uses_std(int);
template <class T>
struct is_std_swap_noexcept
: std::integral_constant<bool, std::is_nothrow_move_constructible<T>::value && std::is_nothrow_move_assignable<T>::value> {};
template <class T, std::size_t N>
struct is_std_swap_noexcept<T[N]> : is_std_swap_noexcept<T> {};
template <class T, class U>
struct is_adl_swap_noexcept : std::integral_constant<bool, noexcept(can_swap<T, U>(0))> {};
} // namespace swap_adl_tests
template <class T, class U = T>
struct is_swappable : std::integral_constant<bool,
decltype(detail::swap_adl_tests::can_swap<T, U>(0))::value
&& (!decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value
|| (std::is_move_assignable<T>::value && std::is_move_constructible<T>::value))> {};
template <class T, std::size_t N>
struct is_swappable<T[N], T[N]> : std::integral_constant<bool,
decltype(detail::swap_adl_tests::can_swap<T[N], T[N]>(0))::value
&& (!decltype(detail::swap_adl_tests::uses_std<T[N], T[N]>(0))::value || is_swappable<T, T>::value)> {};
template <class T, class U = T>
struct is_nothrow_swappable
: std::integral_constant<bool,
is_swappable<T, U>::value
&& ((decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value&& detail::swap_adl_tests::is_std_swap_noexcept<T>::value)
|| (!decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value&& detail::swap_adl_tests::is_adl_swap_noexcept<T, U>::value))> {};
#endif
// 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 <class T, bool = ::std::is_trivially_destructible<T>::value>
struct optional_storage_base {
SOL_TL_OPTIONAL_11_CONSTEXPR optional_storage_base() noexcept : m_dummy(), m_has_value(false) {
}
template <class... U>
SOL_TL_OPTIONAL_11_CONSTEXPR optional_storage_base(in_place_t, U&&... u) : m_value(std::forward<U>(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 <class T>
struct optional_storage_base<T, true> {
SOL_TL_OPTIONAL_11_CONSTEXPR optional_storage_base() noexcept : m_dummy(), m_has_value(false) {
}
template <class... U>
SOL_TL_OPTIONAL_11_CONSTEXPR optional_storage_base(in_place_t, U&&... u) : m_value(std::forward<U>(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 <class T>
struct optional_operations_base : optional_storage_base<T> {
using optional_storage_base<T>::optional_storage_base;
void hard_reset() noexcept {
get().~T();
this->m_has_value = false;
}
template <class... Args>
void construct(Args&&... args) noexcept {
new (std::addressof(this->m_value)) T(std::forward<Args>(args)...);
this->m_has_value = true;
}
template <class Opt>
void assign(Opt&& rhs) {
if (this->has_value()) {
if (rhs.has_value()) {
this->m_value = std::forward<Opt>(rhs).get();
}
else {
this->m_value.~T();
this->m_has_value = false;
}
}
else if (rhs.has_value()) {
construct(std::forward<Opt>(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 <class T, bool = SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)>
struct optional_copy_base : optional_operations_base<T> {
using optional_operations_base<T>::optional_operations_base;
};
// This specialization is for when T is not trivially copy constructible
template <class T>
struct optional_copy_base<T, false> : optional_operations_base<T> {
using optional_operations_base<T>::optional_operations_base;
optional_copy_base() = default;
optional_copy_base(const optional_copy_base& rhs) {
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 <class T, bool = std::is_trivially_move_constructible<T>::value>
struct optional_move_base : optional_copy_base<T> {
using optional_copy_base<T>::optional_copy_base;
};
#else
template <class T, bool = false>
struct optional_move_base;
#endif
template <class T>
struct optional_move_base<T, false> : optional_copy_base<T> {
using optional_copy_base<T>::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<T>::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 <class T,
bool = SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_ASSIGNABLE(T) && SOL_TL_OPTIONAL_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T) && SOL_TL_OPTIONAL_IS_TRIVIALLY_DESTRUCTIBLE(T)>
struct optional_copy_assign_base : optional_move_base<T> {
using optional_move_base<T>::optional_move_base;
};
template <class T>
struct optional_copy_assign_base<T, false> : optional_move_base<T> {
using optional_move_base<T>::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 <class T,
bool = std::is_trivially_destructible<T>::value&& std::is_trivially_move_constructible<T>::value&& std::is_trivially_move_assignable<T>::value>
struct optional_move_assign_base : optional_copy_assign_base<T> {
using optional_copy_assign_base<T>::optional_copy_assign_base;
};
#else
template <class T, bool = false>
struct optional_move_assign_base;
#endif
template <class T>
struct optional_move_assign_base<T, false> : optional_copy_assign_base<T> {
using optional_copy_assign_base<T>::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<T>::value&& std::is_nothrow_move_assignable<T>::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 <class T, bool EnableCopy = std::is_copy_constructible<T>::value, bool EnableMove = std::is_move_constructible<T>::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 <class T>
struct optional_delete_ctor_base<T, true, false> {
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 <class T>
struct optional_delete_ctor_base<T, false, true> {
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 <class T>
struct optional_delete_ctor_base<T, false, false> {
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 <class T, bool EnableCopy = (std::is_copy_constructible<T>::value && std::is_copy_assignable<T>::value),
bool EnableMove = (std::is_move_constructible<T>::value && std::is_move_assignable<T>::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 <class T>
struct optional_delete_assign_base<T, true, false> {
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 <class T>
struct optional_delete_assign_base<T, false, true> {
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 <class T>
struct optional_delete_assign_base<T, false, false> {
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
struct nullopt_t {
struct do_not_use {};
constexpr explicit nullopt_t(do_not_use, do_not_use) noexcept {
}
};
/// \brief Represents an empty optional
/// \synopsis static constexpr nullopt_t nullopt;
///
/// *Examples*:
/// ```
/// sol::optional<int> a = sol::nullopt;
/// void foo (sol::optional<int>);
/// foo(sol::nullopt); //pass an empty optional
/// ```
static constexpr nullopt_t nullopt{ nullopt_t::do_not_use{}, nullopt_t::do_not_use{} };
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 T>
class optional : private detail::optional_move_assign_base<T>,
private detail::optional_delete_ctor_base<T>,
private detail::optional_delete_assign_base<T> {
using base = detail::optional_move_assign_base<T>;
static_assert(!std::is_same<T, in_place_t>::value, "instantiation of optional with in_place_t is ill-formed");
static_assert(!std::is_same<detail::decay_t<T>, 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>(f),
/// value())` returns a `std::optional<U>` for some `U`. \returns Let `U` be
/// the result of `std::invoke(std::forward<F>(f), value())`. Returns a
/// `std::optional<U>`. The return value is empty if `*this` is empty,
/// otherwise the return value of `std::invoke(std::forward<F>(f), value())`
/// is returned.
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR auto and_then(F&& f) & {
using result = detail::invoke_result_t<F, T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &&;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR auto and_then(F&& f) && {
using result = detail::invoke_result_t<F, T&&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : result(nullopt);
}
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &;
template <class F>
constexpr auto and_then(F&& f) const& {
using result = detail::invoke_result_t<F, const T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &&;
template <class F>
constexpr auto and_then(F&& f) const&& {
using result = detail::invoke_result_t<F, const T&&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(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>(f),
/// value())` returns a `std::optional<U>` for some `U`.
/// \returns Let `U` be the result of `std::invoke(std::forward<F>(f),
/// value())`. Returns a `std::optional<U>`. The return value is empty if
/// `*this` is empty, otherwise the return value of
/// `std::invoke(std::forward<F>(f), value())` is returned.
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t<F, T&> and_then(F&& f) & {
using result = detail::invoke_result_t<F, T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &&;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t<F, T&&> and_then(F&& f) && {
using result = detail::invoke_result_t<F, T&&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : result(nullopt);
}
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &;
template <class F>
constexpr detail::invoke_result_t<F, const T&> and_then(F&& f) const& {
using result = detail::invoke_result_t<F, const T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &&;
template <class F>
constexpr detail::invoke_result_t<F, const T&&> and_then(F&& f) const&& {
using result = detail::invoke_result_t<F, const T&&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(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>(f),
/// value())`. Returns a `std::optional<U>`. The return value is empty if
/// `*this` is empty, otherwise an `optional<U>` is constructed from the
/// return value of `std::invoke(std::forward<F>(f), value())` and is
/// returned.
///
/// \group map
/// \synopsis template <class F> constexpr auto map(F &&f) &;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR auto map(F&& f) & {
return optional_map_impl(*this, std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> constexpr auto map(F &&f) &&;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR auto map(F&& f) && {
return optional_map_impl(std::move(*this), std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> constexpr auto map(F &&f) const&;
template <class F>
constexpr auto map(F&& f) const& {
return optional_map_impl(*this, std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> constexpr auto map(F &&f) const&&;
template <class F>
constexpr auto map(F&& f) const&& {
return optional_map_impl(std::move(*this), std::forward<F>(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>(f),
/// value())`. Returns a `std::optional<U>`. The return value is empty if
/// `*this` is empty, otherwise an `optional<U>` is constructed from the
/// return value of `std::invoke(std::forward<F>(f), value())` and is
/// returned.
///
/// \group map
/// \synopsis template <class F> auto map(F &&f) &;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR decltype(optional_map_impl(std::declval<optional&>(), std::declval<F&&>())) map(F&& f) & {
return optional_map_impl(*this, std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> auto map(F &&f) &&;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR decltype(optional_map_impl(std::declval<optional&&>(), std::declval<F&&>())) map(F&& f) && {
return optional_map_impl(std::move(*this), std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> auto map(F &&f) const&;
template <class F>
constexpr decltype(optional_map_impl(std::declval<const optional&>(), std::declval<F&&>())) map(F&& f) const& {
return optional_map_impl(*this, std::forward<F>(f));
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group map
/// \synopsis template <class F> auto map(F &&f) const&&;
template <class F>
constexpr decltype(optional_map_impl(std::declval<const optional&&>(), std::declval<F&&>())) map(F&& f) const&& {
return optional_map_impl(std::move(*this), std::forward<F>(f));
}
#endif
#endif
/// \brief Calls `f` if the optional is empty
/// \requires `std::invoke_result_t<F>` must be void or convertible to
/// `optional<T>`.
/// \effects If `*this` has a value, returns `*this`.
/// Otherwise, if `f` returns `void`, calls `std::forward<F>(f)` and returns
/// `std::nullopt`. Otherwise, returns `std::forward<F>(f)()`.
///
/// \group or_else
/// \synopsis template <class F> optional<T> or_else (F &&f) &;
template <class F, detail::enable_if_ret_void<F>* = nullptr>
optional<T> SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) & {
if (has_value())
return *this;
std::forward<F>(f)();
return nullopt;
}
/// \exclude
template <class F, detail::disable_if_ret_void<F>* = nullptr>
optional<T> SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) & {
return has_value() ? *this : std::forward<F>(f)();
}
/// \group or_else
/// \synopsis template <class F> optional<T> or_else (F &&f) &&;
template <class F, detail::enable_if_ret_void<F>* = nullptr>
optional<T> or_else(F&& f) && {
if (has_value())
return std::move(*this);
std::forward<F>(f)();
return nullopt;
}
/// \exclude
template <class F, detail::disable_if_ret_void<F>* = nullptr>
optional<T> SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) && {
return has_value() ? std::move(*this) : std::forward<F>(f)();
}
/// \group or_else
/// \synopsis template <class F> optional<T> or_else (F &&f) const &;
template <class F, detail::enable_if_ret_void<F>* = nullptr>
optional<T> or_else(F&& f) const& {
if (has_value())
return *this;
std::forward<F>(f)();
return nullopt;
}
/// \exclude
template <class F, detail::disable_if_ret_void<F>* = nullptr>
optional<T> SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) const& {
return has_value() ? *this : std::forward<F>(f)();
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \exclude
template <class F, detail::enable_if_ret_void<F>* = nullptr>
optional<T> or_else(F&& f) const&& {
if (has_value())
return std::move(*this);
std::forward<F>(f)();
return nullopt;
}
/// \exclude
template <class F, detail::disable_if_ret_void<F>* = nullptr>
optional<T> or_else(F&& f) const&& {
return has_value() ? std::move(*this) : std::forward<F>(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 <class F, class U>
U map_or(F&& f, U&& u) & {
return has_value() ? detail::invoke(std::forward<F>(f), **this) : std::forward<U>(u);
}
/// \group map_or
template <class F, class U>
U map_or(F&& f, U&& u) && {
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : std::forward<U>(u);
}
/// \group map_or
template <class F, class U>
U map_or(F&& f, U&& u) const& {
return has_value() ? detail::invoke(std::forward<F>(f), **this) : std::forward<U>(u);
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group map_or
template <class F, class U>
U map_or(F&& f, U&& u) const&& {
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : std::forward<U>(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>(u)()` is returned.
///
/// \group map_or_else
/// \synopsis template <class F, class U>\nauto map_or_else(F &&f, U &&u) &;
template <class F, class U>
detail::invoke_result_t<U> map_or_else(F&& f, U&& u) & {
return has_value() ? detail::invoke(std::forward<F>(f), **this) : std::forward<U>(u)();
}
/// \group map_or_else
/// \synopsis template <class F, class U>\nauto map_or_else(F &&f, U &&u)
/// &&;
template <class F, class U>
detail::invoke_result_t<U> map_or_else(F&& f, U&& u) && {
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : std::forward<U>(u)();
}
/// \group map_or_else
/// \synopsis template <class F, class U>\nauto map_or_else(F &&f, U &&u)
/// const &;
template <class F, class U>
detail::invoke_result_t<U> map_or_else(F&& f, U&& u) const& {
return has_value() ? detail::invoke(std::forward<F>(f), **this) : std::forward<U>(u)();
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group map_or_else
/// \synopsis template <class F, class U>\nauto map_or_else(F &&f, U &&u)
/// const &&;
template <class F, class U>
detail::invoke_result_t<U> map_or_else(F&& f, U&& u) const&& {
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : std::forward<U>(u)();
}
#endif
/// \returns `u` if `*this` has a value, otherwise an empty optional.
template <class U>
constexpr optional<typename std::decay<U>::type> conjunction(U&& u) const {
using result = optional<detail::decay_t<U>>;
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 <class... Args> constexpr explicit optional(in_place_t, Args&&... args);
template <class... Args>
constexpr explicit optional(detail::enable_if_t<std::is_constructible<T, Args...>::value, in_place_t>, Args&&... args)
: base(in_place, std::forward<Args>(args)...) {
}
/// \group in_place
/// \synopsis template <class U, class... Args>\nconstexpr explicit optional(in_place_t, std::initializer_list<U>&, Args&&... args);
template <class U, class... Args>
SOL_TL_OPTIONAL_11_CONSTEXPR explicit optional(detail::enable_if_t<std::is_constructible<T, std::initializer_list<U>&, Args&&...>::value, in_place_t>,
std::initializer_list<U> il, Args&&... args) {
this->construct(il, std::forward<Args>(args)...);
}
#if 0 // SOL_MODIFICATION
/// Constructs the stored value with `u`.
/// \synopsis template <class U=T> constexpr optional(U &&u);
template <class U = T, detail::enable_if_t<std::is_convertible<U&&, T>::value>* = nullptr, detail::enable_forward_value<T, U>* = nullptr>
constexpr optional(U&& u) : base(in_place, std::forward<U>(u)) {
}
/// \exclude
template <class U = T, detail::enable_if_t<!std::is_convertible<U&&, T>::value>* = nullptr, detail::enable_forward_value<T, U>* = nullptr>
constexpr explicit optional(U&& u) : base(in_place, std::forward<U>(u)) {
}
#else
/// Constructs the stored value with `u`.
/// \synopsis template <class U=T> 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 // sol2 modification
/// Converting copy constructor.
/// \synopsis template <class U> optional(const optional<U> &rhs);
template <class U, detail::enable_from_other<T, U, const U&>* = nullptr, detail::enable_if_t<std::is_convertible<const U&, T>::value>* = nullptr>
optional(const optional<U>& rhs) {
if (rhs.has_value()) {
this->construct(*rhs);
}
}
/// \exclude
template <class U, detail::enable_from_other<T, U, const U&>* = nullptr, detail::enable_if_t<!std::is_convertible<const U&, T>::value>* = nullptr>
explicit optional(const optional<U>& rhs) {
if (rhs.has_value()) {
this->construct(*rhs);
}
}
/// Converting move constructor.
/// \synopsis template <class U> optional(optional<U> &&rhs);
template <class U, detail::enable_from_other<T, U, U&&>* = nullptr, detail::enable_if_t<std::is_convertible<U&&, T>::value>* = nullptr>
optional(optional<U>&& rhs) {
if (rhs.has_value()) {
this->construct(std::move(*rhs));
}
}
/// \exclude
template <class U, detail::enable_from_other<T, U, U&&>* = nullptr, detail::enable_if_t<!std::is_convertible<U&&, T>::value>* = nullptr>
explicit optional(optional<U>&& 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 <class U = T, detail::enable_assign_forward<T, U>* = nullptr>
optional& operator=(U&& u) {
if (has_value()) {
this->m_value = std::forward<U>(u);
}
else {
this->construct(std::forward<U>(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<U> & rhs);
template <class U, detail::enable_assign_from_other<T, U, const U&>* = nullptr>
optional& operator=(const optional<U>& 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<U> && rhs);
template <class U, detail::enable_assign_from_other<T, U, U>* = nullptr>
optional& operator=(optional<U>&& 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 <class... Args>
T& emplace(Args&&... args) {
static_assert(std::is_constructible<T, Args&&...>::value, "T must be constructible with Args");
*this = nullopt;
this->construct(std::forward<Args>(args)...);
return value();
}
/// \group emplace
/// \synopsis template <class U, class... Args>\nT& emplace(std::initializer_list<U> il, Args &&... args);
template <class U, class... Args>
detail::enable_if_t<std::is_constructible<T, std::initializer_list<U>&, Args&&...>::value, T&> emplace(std::initializer_list<U> il, Args&&... args) {
*this = nullopt;
this->construct(il, std::forward<Args>(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<T>::value&& detail::is_nothrow_swappable<T>::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;
throw bad_optional_access();
}
/// \group value
/// \synopsis constexpr const T &value() const;
SOL_TL_OPTIONAL_11_CONSTEXPR const T& value() const& {
if (has_value())
return this->m_value;
throw bad_optional_access();
}
/// \exclude
SOL_TL_OPTIONAL_11_CONSTEXPR T&& value() && {
if (has_value())
return std::move(this->m_value);
throw bad_optional_access();
}
#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);
throw bad_optional_access();
}
#endif
/// \returns the stored value if there is one, otherwise returns `u`
/// \group value_or
template <class U>
constexpr T& value_or(U&& u) const& {
static_assert(std::is_copy_constructible<T>::value && std::is_convertible<U&&, T>::value, "T must be copy constructible and convertible from U");
return has_value() ? **this : static_cast<T>(std::forward<U>(u));
}
/// \group value_or
template <class U>
SOL_TL_OPTIONAL_11_CONSTEXPR T& value_or(U&& u) && {
static_assert(std::is_move_constructible<T>::value && std::is_convertible<U&&, T>::value, "T must be move constructible and convertible from U");
return has_value() ? **this : static_cast<T>(std::forward<U>(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 <class T, class U>
inline constexpr bool operator==(const optional<T>& lhs, const optional<U>& rhs) {
return lhs.has_value() == rhs.has_value() && (!lhs.has_value() || *lhs == *rhs);
}
/// \group relop
template <class T, class U>
inline constexpr bool operator!=(const optional<T>& lhs, const optional<U>& rhs) {
return lhs.has_value() != rhs.has_value() || (lhs.has_value() && *lhs != *rhs);
}
/// \group relop
template <class T, class U>
inline constexpr bool operator<(const optional<T>& lhs, const optional<U>& rhs) {
return rhs.has_value() && (!lhs.has_value() || *lhs < *rhs);
}
/// \group relop
template <class T, class U>
inline constexpr bool operator>(const optional<T>& lhs, const optional<U>& rhs) {
return lhs.has_value() && (!rhs.has_value() || *lhs > *rhs);
}
/// \group relop
template <class T, class U>
inline constexpr bool operator<=(const optional<T>& lhs, const optional<U>& rhs) {
return !lhs.has_value() || (rhs.has_value() && *lhs <= *rhs);
}
/// \group relop
template <class T, class U>
inline constexpr bool operator>=(const optional<T>& lhs, const optional<U>& 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 <class T>
inline constexpr bool operator==(const optional<T>& lhs, nullopt_t) noexcept {
return !lhs.has_value();
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator==(nullopt_t, const optional<T>& rhs) noexcept {
return !rhs.has_value();
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator!=(const optional<T>& lhs, nullopt_t) noexcept {
return lhs.has_value();
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator!=(nullopt_t, const optional<T>& rhs) noexcept {
return rhs.has_value();
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator<(const optional<T>&, nullopt_t) noexcept {
return false;
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator<(nullopt_t, const optional<T>& rhs) noexcept {
return rhs.has_value();
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator<=(const optional<T>& lhs, nullopt_t) noexcept {
return !lhs.has_value();
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator<=(nullopt_t, const optional<T>&) noexcept {
return true;
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator>(const optional<T>& lhs, nullopt_t) noexcept {
return lhs.has_value();
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator>(nullopt_t, const optional<T>&) noexcept {
return false;
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator>=(const optional<T>&, nullopt_t) noexcept {
return true;
}
/// \group relop_nullopt
template <class T>
inline constexpr bool operator>=(nullopt_t, const optional<T>& 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 <class T, class U>
inline constexpr bool operator==(const optional<T>& lhs, const U& rhs) {
return lhs.has_value() ? *lhs == rhs : false;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator==(const U& lhs, const optional<T>& rhs) {
return rhs.has_value() ? lhs == *rhs : false;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator!=(const optional<T>& lhs, const U& rhs) {
return lhs.has_value() ? *lhs != rhs : true;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator!=(const U& lhs, const optional<T>& rhs) {
return rhs.has_value() ? lhs != *rhs : true;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator<(const optional<T>& lhs, const U& rhs) {
return lhs.has_value() ? *lhs < rhs : true;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator<(const U& lhs, const optional<T>& rhs) {
return rhs.has_value() ? lhs < *rhs : false;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator<=(const optional<T>& lhs, const U& rhs) {
return lhs.has_value() ? *lhs <= rhs : true;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator<=(const U& lhs, const optional<T>& rhs) {
return rhs.has_value() ? lhs <= *rhs : false;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator>(const optional<T>& lhs, const U& rhs) {
return lhs.has_value() ? *lhs > rhs : false;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator>(const U& lhs, const optional<T>& rhs) {
return rhs.has_value() ? lhs > *rhs : true;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator>=(const optional<T>& lhs, const U& rhs) {
return lhs.has_value() ? *lhs >= rhs : false;
}
/// \group relop_t
template <class T, class U>
inline constexpr bool operator>=(const U& lhs, const optional<T>& rhs) {
return rhs.has_value() ? lhs >= *rhs : true;
}
/// \synopsis template <class T>\nvoid swap(optional<T> &lhs, optional<T> &rhs);
template <class T, detail::enable_if_t<std::is_move_constructible<T>::value>* = nullptr, detail::enable_if_t<detail::is_swappable<T>::value>* = nullptr>
void swap(optional<T>& lhs, optional<T>& rhs) noexcept(noexcept(lhs.swap(rhs))) {
return lhs.swap(rhs);
}
namespace detail {
struct i_am_secret {};
} // namespace detail
template <class T = detail::i_am_secret, class U, class Ret = detail::conditional_t<std::is_same<T, detail::i_am_secret>::value, detail::decay_t<U>, T>>
inline constexpr optional<Ret> make_optional(U&& v) {
return optional<Ret>(std::forward<U>(v));
}
template <class T, class... Args>
inline constexpr optional<T> make_optional(Args&&... args) {
return optional<T>(in_place, std::forward<Args>(args)...);
}
template <class T, class U, class... Args>
inline constexpr optional<T> make_optional(std::initializer_list<U> il, Args&&... args) {
return optional<T>(in_place, il, std::forward<Args>(args)...);
}
#if __cplusplus >= 201703L
template <class T>
optional(T)->optional<T>;
#endif
/// \exclude
namespace detail {
#ifdef SOL_TL_OPTIONAL_CXX14
template <class Opt, class F, class Ret = decltype(detail::invoke(std::declval<F>(), *std::declval<Opt>())),
detail::enable_if_t<!std::is_void<Ret>::value>* = nullptr>
constexpr auto optional_map_impl(Opt&& opt, F&& f) {
return opt.has_value() ? detail::invoke(std::forward<F>(f), *std::forward<Opt>(opt)) : optional<Ret>(nullopt);
}
template <class Opt, class F, class Ret = decltype(detail::invoke(std::declval<F>(), *std::declval<Opt>())),
detail::enable_if_t<std::is_void<Ret>::value>* = nullptr>
auto optional_map_impl(Opt&& opt, F&& f) {
if (opt.has_value()) {
detail::invoke(std::forward<F>(f), *std::forward<Opt>(opt));
return make_optional(monostate{});
}
return optional<monostate>(nullopt);
}
#else
template <class Opt, class F, class Ret = decltype(detail::invoke(std::declval<F>(), *std::declval<Opt>())),
detail::enable_if_t<!std::is_void<Ret>::value>* = nullptr>
constexpr auto optional_map_impl(Opt&& opt, F&& f) -> optional<Ret> {
return opt.has_value() ? detail::invoke(std::forward<F>(f), *std::forward<Opt>(opt)) : optional<Ret>(nullopt);
}
template <class Opt, class F, class Ret = decltype(detail::invoke(std::declval<F>(), *std::declval<Opt>())),
detail::enable_if_t<std::is_void<Ret>::value>* = nullptr>
auto optional_map_impl(Opt&& opt, F&& f) -> optional<monostate> {
if (opt.has_value()) {
detail::invoke(std::forward<F>(f), *std::forward<Opt>(opt));
return monostate{};
}
return nullopt;
}
#endif
} // namespace detail
/// Specialization for when `T` is a reference. `optional<T&>` acts similarly
/// to a `T*`, but provides more operations and shows intent more clearly.
///
/// *Examples*:
///
/// ```
/// int i = 42;
/// sol::optional<int&> 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 T>
class optional<T&> {
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>(f),
/// value())` returns a `std::optional<U>` for some `U`. \returns Let `U` be
/// the result of `std::invoke(std::forward<F>(f), value())`. Returns a
/// `std::optional<U>`. The return value is empty if `*this` is empty,
/// otherwise the return value of `std::invoke(std::forward<F>(f), value())`
/// is returned.
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR auto and_then(F&& f) & {
using result = detail::invoke_result_t<F, T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &&;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR auto and_then(F&& f) && {
using result = detail::invoke_result_t<F, T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &;
template <class F>
constexpr auto and_then(F&& f) const& {
using result = detail::invoke_result_t<F, const T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &&;
template <class F>
constexpr auto and_then(F&& f) const&& {
using result = detail::invoke_result_t<F, const T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(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>(f),
/// value())` returns a `std::optional<U>` for some `U`. \returns Let `U` be
/// the result of `std::invoke(std::forward<F>(f), value())`. Returns a
/// `std::optional<U>`. The return value is empty if `*this` is empty,
/// otherwise the return value of `std::invoke(std::forward<F>(f), value())`
/// is returned.
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t<F, T&> and_then(F&& f) & {
using result = detail::invoke_result_t<F, T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &&;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t<F, T&> and_then(F&& f) && {
using result = detail::invoke_result_t<F, T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &;
template <class F>
constexpr detail::invoke_result_t<F, const T&> and_then(F&& f) const& {
using result = detail::invoke_result_t<F, const T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(f), **this) : result(nullopt);
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group and_then
/// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &&;
template <class F>
constexpr detail::invoke_result_t<F, const T&> and_then(F&& f) const&& {
using result = detail::invoke_result_t<F, const T&>;
static_assert(detail::is_optional<result>::value, "F must return an optional");
return has_value() ? detail::invoke(std::forward<F>(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>(f),
/// value())`. Returns a `std::optional<U>`. The return value is empty if
/// `*this` is empty, otherwise an `optional<U>` is constructed from the
/// return value of `std::invoke(std::forward<F>(f), value())` and is
/// returned.
///
/// \group map
/// \synopsis template <class F> constexpr auto map(F &&f) &;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR auto map(F&& f) & {
return detail::optional_map_impl(*this, std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> constexpr auto map(F &&f) &&;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR auto map(F&& f) && {
return detail::optional_map_impl(std::move(*this), std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> constexpr auto map(F &&f) const&;
template <class F>
constexpr auto map(F&& f) const& {
return detail::optional_map_impl(*this, std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> constexpr auto map(F &&f) const&&;
template <class F>
constexpr auto map(F&& f) const&& {
return detail::optional_map_impl(std::move(*this), std::forward<F>(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>(f),
/// value())`. Returns a `std::optional<U>`. The return value is empty if
/// `*this` is empty, otherwise an `optional<U>` is constructed from the
/// return value of `std::invoke(std::forward<F>(f), value())` and is
/// returned.
///
/// \group map
/// \synopsis template <class F> auto map(F &&f) &;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR decltype(detail::optional_map_impl(std::declval<optional&>(), std::declval<F&&>())) map(F&& f) & {
return detail::optional_map_impl(*this, std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> auto map(F &&f) &&;
template <class F>
SOL_TL_OPTIONAL_11_CONSTEXPR decltype(detail::optional_map_impl(std::declval<optional&&>(), std::declval<F&&>())) map(F&& f) && {
return detail::optional_map_impl(std::move(*this), std::forward<F>(f));
}
/// \group map
/// \synopsis template <class F> auto map(F &&f) const&;
template <class F>
constexpr decltype(detail::optional_map_impl(std::declval<const optional&>(), std::declval<F&&>())) map(F&& f) const& {
return detail::optional_map_impl(*this, std::forward<F>(f));
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group map
/// \synopsis template <class F> auto map(F &&f) const&&;
template <class F>
constexpr decltype(detail::optional_map_impl(std::declval<const optional&&>(), std::declval<F&&>())) map(F&& f) const&& {
return detail::optional_map_impl(std::move(*this), std::forward<F>(f));
}
#endif
#endif
/// \brief Calls `f` if the optional is empty
/// \requires `std::invoke_result_t<F>` must be void or convertible to
/// `optional<T>`. \effects If `*this` has a value, returns `*this`.
/// Otherwise, if `f` returns `void`, calls `std::forward<F>(f)` and returns
/// `std::nullopt`. Otherwise, returns `std::forward<F>(f)()`.
///
/// \group or_else
/// \synopsis template <class F> optional<T> or_else (F &&f) &;
template <class F, detail::enable_if_ret_void<F>* = nullptr>
optional<T> SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) & {
if (has_value())
return *this;
std::forward<F>(f)();
return nullopt;
}
/// \exclude
template <class F, detail::disable_if_ret_void<F>* = nullptr>
optional<T> SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) & {
return has_value() ? *this : std::forward<F>(f)();
}
/// \group or_else
/// \synopsis template <class F> optional<T> or_else (F &&f) &&;
template <class F, detail::enable_if_ret_void<F>* = nullptr>
optional<T> or_else(F&& f) && {
if (has_value())
return std::move(*this);
std::forward<F>(f)();
return nullopt;
}
/// \exclude
template <class F, detail::disable_if_ret_void<F>* = nullptr>
optional<T> SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) && {
return has_value() ? std::move(*this) : std::forward<F>(f)();
}
/// \group or_else
/// \synopsis template <class F> optional<T> or_else (F &&f) const &;
template <class F, detail::enable_if_ret_void<F>* = nullptr>
optional<T> or_else(F&& f) const& {
if (has_value())
return *this;
std::forward<F>(f)();
return nullopt;
}
/// \exclude
template <class F, detail::disable_if_ret_void<F>* = nullptr>
optional<T> SOL_TL_OPTIONAL_11_CONSTEXPR or_else(F&& f) const& {
return has_value() ? *this : std::forward<F>(f)();
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \exclude
template <class F, detail::enable_if_ret_void<F>* = nullptr>
optional<T> or_else(F&& f) const&& {
if (has_value())
return std::move(*this);
std::forward<F>(f)();
return nullopt;
}
/// \exclude
template <class F, detail::disable_if_ret_void<F>* = nullptr>
optional<T> or_else(F&& f) const&& {
return has_value() ? std::move(*this) : std::forward<F>(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 <class F, class U>
U map_or(F&& f, U&& u) & {
return has_value() ? detail::invoke(std::forward<F>(f), **this) : std::forward<U>(u);
}
/// \group map_or
template <class F, class U>
U map_or(F&& f, U&& u) && {
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : std::forward<U>(u);
}
/// \group map_or
template <class F, class U>
U map_or(F&& f, U&& u) const& {
return has_value() ? detail::invoke(std::forward<F>(f), **this) : std::forward<U>(u);
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group map_or
template <class F, class U>
U map_or(F&& f, U&& u) const&& {
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : std::forward<U>(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>(u)()` is returned.
///
/// \group map_or_else
/// \synopsis template <class F, class U>\nauto map_or_else(F &&f, U &&u) &;
template <class F, class U>
detail::invoke_result_t<U> map_or_else(F&& f, U&& u) & {
return has_value() ? detail::invoke(std::forward<F>(f), **this) : std::forward<U>(u)();
}
/// \group map_or_else
/// \synopsis template <class F, class U>\nauto map_or_else(F &&f, U &&u)
/// &&;
template <class F, class U>
detail::invoke_result_t<U> map_or_else(F&& f, U&& u) && {
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : std::forward<U>(u)();
}
/// \group map_or_else
/// \synopsis template <class F, class U>\nauto map_or_else(F &&f, U &&u)
/// const &;
template <class F, class U>
detail::invoke_result_t<U> map_or_else(F&& f, U&& u) const& {
return has_value() ? detail::invoke(std::forward<F>(f), **this) : std::forward<U>(u)();
}
#ifndef SOL_TL_OPTIONAL_NO_CONSTRR
/// \group map_or_else
/// \synopsis template <class F, class U>\nauto map_or_else(F &&f, U &&u)
/// const &&;
template <class F, class U>
detail::invoke_result_t<U> map_or_else(F&& f, U&& u) const&& {
return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this)) : std::forward<U>(u)();
}
#endif
/// \returns `u` if `*this` has a value, otherwise an empty optional.
template <class U>
constexpr optional<typename std::decay<U>::type> conjunction(U&& u) const {
using result = optional<detail::decay_t<U>>;
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 <class U=T> constexpr optional(U &&u);
template <class U = T, detail::enable_if_t<!detail::is_optional<detail::decay_t<U>>::value>* = nullptr>
constexpr optional(U&& u) : m_value(std::addressof(u)) {
static_assert(std::is_lvalue_reference<U>::value, "U must be an lvalue");
}
/// \exclude
template <class U>
constexpr explicit optional(const optional<U>& 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 <class U = T, detail::enable_if_t<!detail::is_optional<detail::decay_t<U>>::value>* = nullptr>
optional& operator=(U&& u) {
static_assert(std::is_lvalue_reference<U>::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 <class U>
optional& operator=(const optional<U>& 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 <class... Args>
T& emplace(Args&&... args) noexcept {
static_assert(std::is_constructible<T, Args&&...>::value, "T must be constructible with Args");
*this = nullopt;
this->construct(std::forward<Args>(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;
throw bad_optional_access();
}
/// \group value
/// \synopsis constexpr const T &value() const;
SOL_TL_OPTIONAL_11_CONSTEXPR const T& value() const {
if (has_value())
return *m_value;
throw bad_optional_access();
}
/// \returns the stored value if there is one, otherwise returns `u`
/// \group value_or
template <class U>
constexpr T& value_or(U&& u) const& {
static_assert(std::is_copy_constructible<T>::value && std::is_convertible<U&&, T>::value, "T must be copy constructible and convertible from U");
return has_value() ? **this : static_cast<T>(std::forward<U>(u));
}
/// \group value_or
template <class U>
SOL_TL_OPTIONAL_11_CONSTEXPR T& value_or(U&& u) && {
static_assert(std::is_move_constructible<T>::value && std::is_convertible<U&&, T>::value, "T must be move constructible and convertible from U");
return has_value() ? **this : static_cast<T>(std::forward<U>(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 <class T>
struct hash< ::sol::optional<T> > {
::std::size_t operator()(const ::sol::optional<T>& o) const {
if (!o.has_value())
return 0;
return ::std::hash< ::sol::detail::remove_const_t<T>>()(*o);
}
};
} // namespace std
#endif // SOL_TL_OPTIONAL_HPP
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