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llvm-project/libcxx/include/optional
Louis Dionne de4a57cb21 [libc++] Re-add transitive includes that had been removed since LLVM 14 
This commit re-adds transitive includes that had been removed by
4cd04d1687f1, c36870c8e79c, a83f4b9cda57, 1458458b558d, 2e2f3158c604,
and 489637e66dd3. This should cover almost all the includes that had
been removed since LLVM 14 and that would contribute to breaking user
code when releasing LLVM 15.

It is possible to disable the inclusion of these headers by defining
_LIBCPP_REMOVE_TRANSITIVE_INCLUDES. The intent is that vendors will
enable that macro and start fixing downstream issues immediately. We
can then remove the macro (and the transitive includes) by default in
a future release. That way, we will break users only once by removing
transitive includes in bulk instead of doing it bit by bit a every
release, which is more disruptive for users.

Note 1: The set of headers to re-add was found by re-generating the
        transitive include test on a checkout of release/14.x, which
        provided the list of all transitive includes we used to provide.

Note 2: Several includes of <vector>, <optional>, <array> and <unordered_map>
        have been added in this commit. These transitive inclusions were
        added when we implemented boyer_moore_searcher in <functional>.

Note 3: This is a best effort patch to try and resolve downstream breakage
        caused since branching LLVM 14. I wasn't able to perfectly mirror
        transitive includes in LLVM 14 for a few headers, so I added a
        release note explaining it. To summarize, adding boyer_moore_searcher
        created a bunch of circular dependencies, so we have to break
        backwards compatibility in a few cases.

Differential Revision: https://reviews.llvm.org/D128661
2022-06-27 22:18:19 -04:00

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// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_OPTIONAL
#define _LIBCPP_OPTIONAL
/*
optional synopsis
// C++1z
namespace std {
// 23.6.3, optional for object types
template <class T> class optional;
// 23.6.4, no-value state indicator
struct nullopt_t{see below };
inline constexpr nullopt_t nullopt(unspecified );
// 23.6.5, class bad_optional_access
class bad_optional_access;
// 23.6.6, relational operators
template <class T, class U>
constexpr bool operator==(const optional<T>&, const optional<U>&);
template <class T, class U>
constexpr bool operator!=(const optional<T>&, const optional<U>&);
template <class T, class U>
constexpr bool operator<(const optional<T>&, const optional<U>&);
template <class T, class U>
constexpr bool operator>(const optional<T>&, const optional<U>&);
template <class T, class U>
constexpr bool operator<=(const optional<T>&, const optional<U>&);
template <class T, class U>
constexpr bool operator>=(const optional<T>&, const optional<U>&);
// 23.6.7 comparison with nullopt
template <class T> constexpr bool operator==(const optional<T>&, nullopt_t) noexcept;
template <class T> constexpr bool operator==(nullopt_t, const optional<T>&) noexcept;
template <class T> constexpr bool operator!=(const optional<T>&, nullopt_t) noexcept;
template <class T> constexpr bool operator!=(nullopt_t, const optional<T>&) noexcept;
template <class T> constexpr bool operator<(const optional<T>&, nullopt_t) noexcept;
template <class T> constexpr bool operator<(nullopt_t, const optional<T>&) noexcept;
template <class T> constexpr bool operator<=(const optional<T>&, nullopt_t) noexcept;
template <class T> constexpr bool operator<=(nullopt_t, const optional<T>&) noexcept;
template <class T> constexpr bool operator>(const optional<T>&, nullopt_t) noexcept;
template <class T> constexpr bool operator>(nullopt_t, const optional<T>&) noexcept;
template <class T> constexpr bool operator>=(const optional<T>&, nullopt_t) noexcept;
template <class T> constexpr bool operator>=(nullopt_t, const optional<T>&) noexcept;
// 23.6.8, comparison with T
template <class T, class U> constexpr bool operator==(const optional<T>&, const U&);
template <class T, class U> constexpr bool operator==(const T&, const optional<U>&);
template <class T, class U> constexpr bool operator!=(const optional<T>&, const U&);
template <class T, class U> constexpr bool operator!=(const T&, const optional<U>&);
template <class T, class U> constexpr bool operator<(const optional<T>&, const U&);
template <class T, class U> constexpr bool operator<(const T&, const optional<U>&);
template <class T, class U> constexpr bool operator<=(const optional<T>&, const U&);
template <class T, class U> constexpr bool operator<=(const T&, const optional<U>&);
template <class T, class U> constexpr bool operator>(const optional<T>&, const U&);
template <class T, class U> constexpr bool operator>(const T&, const optional<U>&);
template <class T, class U> constexpr bool operator>=(const optional<T>&, const U&);
template <class T, class U> constexpr bool operator>=(const T&, const optional<U>&);
// 23.6.9, specialized algorithms
template <class T> void swap(optional<T>&, optional<T>&) noexcept(see below ); // constexpr in C++20
template <class T> constexpr optional<see below > make_optional(T&&);
template <class T, class... Args>
constexpr optional<T> make_optional(Args&&... args);
template <class T, class U, class... Args>
constexpr optional<T> make_optional(initializer_list<U> il, Args&&... args);
// 23.6.10, hash support
template <class T> struct hash;
template <class T> struct hash<optional<T>>;
template <class T> class optional {
public:
using value_type = T;
// 23.6.3.1, constructors
constexpr optional() noexcept;
constexpr optional(nullopt_t) noexcept;
optional(const optional &);
optional(optional &&) noexcept(see below);
template <class... Args> constexpr explicit optional(in_place_t, Args &&...);
template <class U, class... Args>
constexpr explicit optional(in_place_t, initializer_list<U>, Args &&...);
template <class U = T>
constexpr explicit(see-below) optional(U &&);
template <class U>
explicit(see-below) optional(const optional<U> &); // constexpr in C++20
template <class U>
explicit(see-below) optional(optional<U> &&); // constexpr in C++20
// 23.6.3.2, destructor
~optional(); // constexpr in C++20
// 23.6.3.3, assignment
optional &operator=(nullopt_t) noexcept; // constexpr in C++20
optional &operator=(const optional &); // constexpr in C++20
optional &operator=(optional &&) noexcept(see below); // constexpr in C++20
template <class U = T> optional &operator=(U &&); // constexpr in C++20
template <class U> optional &operator=(const optional<U> &); // constexpr in C++20
template <class U> optional &operator=(optional<U> &&); // constexpr in C++20
template <class... Args> T& emplace(Args &&...); // constexpr in C++20
template <class U, class... Args>
T& emplace(initializer_list<U>, Args &&...); // constexpr in C++20
// 23.6.3.4, swap
void swap(optional &) noexcept(see below ); // constexpr in C++20
// 23.6.3.5, observers
constexpr T const *operator->() const;
constexpr T *operator->();
constexpr T const &operator*() const &;
constexpr T &operator*() &;
constexpr T &&operator*() &&;
constexpr const T &&operator*() const &&;
constexpr explicit operator bool() const noexcept;
constexpr bool has_value() const noexcept;
constexpr T const &value() const &;
constexpr T &value() &;
constexpr T &&value() &&;
constexpr const T &&value() const &&;
template <class U> constexpr T value_or(U &&) const &;
template <class U> constexpr T value_or(U &&) &&;
// [optional.monadic], monadic operations
template<class F> constexpr auto and_then(F&& f) &; // since C++23
template<class F> constexpr auto and_then(F&& f) &&; // since C++23
template<class F> constexpr auto and_then(F&& f) const&; // since C++23
template<class F> constexpr auto and_then(F&& f) const&&; // since C++23
template<class F> constexpr auto transform(F&& f) &; // since C++23
template<class F> constexpr auto transform(F&& f) &&; // since C++23
template<class F> constexpr auto transform(F&& f) const&; // since C++23
template<class F> constexpr auto transform(F&& f) const&&; // since C++23
template<class F> constexpr optional or_else(F&& f) &&; // since C++23
template<class F> constexpr optional or_else(F&& f) const&; // since C++23
// 23.6.3.6, modifiers
void reset() noexcept; // constexpr in C++20
private:
T *val; // exposition only
};
template<class T>
optional(T) -> optional<T>;
} // namespace std
*/
#include <__assert> // all public C++ headers provide the assertion handler
#include <__availability>
#include <__concepts/invocable.h>
#include <__config>
#include <__functional/hash.h>
#include <__functional/invoke.h>
#include <__functional/unary_function.h>
#include <__memory/construct_at.h>
#include <__tuple>
#include <__utility/forward.h>
#include <__utility/in_place.h>
#include <__utility/move.h>
#include <__utility/swap.h>
#include <initializer_list>
#include <new>
#include <stdexcept>
#include <type_traits>
#include <version>
#ifndef _LIBCPP_REMOVE_TRANSITIVE_INCLUDES
# include <atomic>
# include <chrono>
# include <climits>
# include <concepts>
# include <ctime>
# include <iterator>
# include <memory>
# include <ratio>
# include <tuple>
# include <typeinfo>
# include <utility>
# include <variant>
#endif
// standard-mandated includes
#include <compare>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
namespace std // purposefully not using versioning namespace
{
class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS bad_optional_access
: public exception
{
public:
// Get the key function ~bad_optional_access() into the dylib
virtual ~bad_optional_access() _NOEXCEPT;
virtual const char* what() const _NOEXCEPT;
};
} // namespace std
#if _LIBCPP_STD_VER > 14
_LIBCPP_BEGIN_NAMESPACE_STD
_LIBCPP_NORETURN
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
void __throw_bad_optional_access() {
#ifndef _LIBCPP_NO_EXCEPTIONS
throw bad_optional_access();
#else
_VSTD::abort();
#endif
}
struct nullopt_t
{
struct __secret_tag { _LIBCPP_INLINE_VISIBILITY explicit __secret_tag() = default; };
_LIBCPP_INLINE_VISIBILITY constexpr explicit nullopt_t(__secret_tag, __secret_tag) noexcept {}
};
inline constexpr nullopt_t nullopt{nullopt_t::__secret_tag{}, nullopt_t::__secret_tag{}};
struct __optional_construct_from_invoke_tag {};
template <class _Tp, bool = is_trivially_destructible<_Tp>::value>
struct __optional_destruct_base;
template <class _Tp>
struct __optional_destruct_base<_Tp, false>
{
typedef _Tp value_type;
static_assert(is_object_v<value_type>,
"instantiation of optional with a non-object type is undefined behavior");
union
{
char __null_state_;
value_type __val_;
};
bool __engaged_;
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 ~__optional_destruct_base()
{
if (__engaged_)
__val_.~value_type();
}
_LIBCPP_INLINE_VISIBILITY
constexpr __optional_destruct_base() noexcept
: __null_state_(),
__engaged_(false) {}
template <class... _Args>
_LIBCPP_INLINE_VISIBILITY
constexpr explicit __optional_destruct_base(in_place_t, _Args&&... __args)
: __val_(_VSTD::forward<_Args>(__args)...),
__engaged_(true) {}
#if _LIBCPP_STD_VER > 20
template <class _Fp, class... _Args>
_LIBCPP_HIDE_FROM_ABI
constexpr __optional_destruct_base(__optional_construct_from_invoke_tag, _Fp&& __f, _Args&&... __args)
: __val_(_VSTD::invoke(_VSTD::forward<_Fp>(__f), _VSTD::forward<_Args>(__args)...)), __engaged_(true) {}
#endif
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void reset() noexcept
{
if (__engaged_)
{
__val_.~value_type();
__engaged_ = false;
}
}
};
template <class _Tp>
struct __optional_destruct_base<_Tp, true>
{
typedef _Tp value_type;
static_assert(is_object_v<value_type>,
"instantiation of optional with a non-object type is undefined behavior");
union
{
char __null_state_;
value_type __val_;
};
bool __engaged_;
_LIBCPP_INLINE_VISIBILITY
constexpr __optional_destruct_base() noexcept
: __null_state_(),
__engaged_(false) {}
template <class... _Args>
_LIBCPP_INLINE_VISIBILITY
constexpr explicit __optional_destruct_base(in_place_t, _Args&&... __args)
: __val_(_VSTD::forward<_Args>(__args)...),
__engaged_(true) {}
#if _LIBCPP_STD_VER > 20
template <class _Fp, class... _Args>
_LIBCPP_HIDE_FROM_ABI
constexpr __optional_destruct_base(__optional_construct_from_invoke_tag, _Fp&& __f, _Args&&... __args)
: __val_(_VSTD::invoke(_VSTD::forward<_Fp>(__f), _VSTD::forward<_Args>(__args)...)), __engaged_(true) {}
#endif
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void reset() noexcept
{
if (__engaged_)
{
__engaged_ = false;
}
}
};
template <class _Tp, bool = is_reference<_Tp>::value>
struct __optional_storage_base : __optional_destruct_base<_Tp>
{
using __base = __optional_destruct_base<_Tp>;
using value_type = _Tp;
using __base::__base;
_LIBCPP_INLINE_VISIBILITY
constexpr bool has_value() const noexcept
{
return this->__engaged_;
}
_LIBCPP_INLINE_VISIBILITY
constexpr value_type& __get() & noexcept
{
return this->__val_;
}
_LIBCPP_INLINE_VISIBILITY
constexpr const value_type& __get() const& noexcept
{
return this->__val_;
}
_LIBCPP_INLINE_VISIBILITY
constexpr value_type&& __get() && noexcept
{
return _VSTD::move(this->__val_);
}
_LIBCPP_INLINE_VISIBILITY
constexpr const value_type&& __get() const&& noexcept
{
return _VSTD::move(this->__val_);
}
template <class... _Args>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct(_Args&&... __args)
{
_LIBCPP_ASSERT(!has_value(), "__construct called for engaged __optional_storage");
#if _LIBCPP_STD_VER > 17
_VSTD::construct_at(_VSTD::addressof(this->__val_), _VSTD::forward<_Args>(__args)...);
#else
::new ((void*)_VSTD::addressof(this->__val_)) value_type(_VSTD::forward<_Args>(__args)...);
#endif
this->__engaged_ = true;
}
template <class _That>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct_from(_That&& __opt)
{
if (__opt.has_value())
__construct(_VSTD::forward<_That>(__opt).__get());
}
template <class _That>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void __assign_from(_That&& __opt)
{
if (this->__engaged_ == __opt.has_value())
{
if (this->__engaged_)
this->__val_ = _VSTD::forward<_That>(__opt).__get();
}
else
{
if (this->__engaged_)
this->reset();
else
__construct(_VSTD::forward<_That>(__opt).__get());
}
}
};
// optional<T&> is currently required to be ill-formed. However, it may
// be allowed in the future. For this reason, it has already been implemented
// to ensure we can make the change in an ABI-compatible manner.
template <class _Tp>
struct __optional_storage_base<_Tp, true>
{
using value_type = _Tp;
using __raw_type = remove_reference_t<_Tp>;
__raw_type* __value_;
template <class _Up>
static constexpr bool __can_bind_reference() {
using _RawUp = typename remove_reference<_Up>::type;
using _UpPtr = _RawUp*;
using _RawTp = typename remove_reference<_Tp>::type;
using _TpPtr = _RawTp*;
using _CheckLValueArg = integral_constant<bool,
(is_lvalue_reference<_Up>::value && is_convertible<_UpPtr, _TpPtr>::value)
|| is_same<_RawUp, reference_wrapper<_RawTp>>::value
|| is_same<_RawUp, reference_wrapper<typename remove_const<_RawTp>::type>>::value
>;
return (is_lvalue_reference<_Tp>::value && _CheckLValueArg::value)
|| (is_rvalue_reference<_Tp>::value && !is_lvalue_reference<_Up>::value &&
is_convertible<_UpPtr, _TpPtr>::value);
}
_LIBCPP_INLINE_VISIBILITY
constexpr __optional_storage_base() noexcept
: __value_(nullptr) {}
template <class _UArg>
_LIBCPP_INLINE_VISIBILITY
constexpr explicit __optional_storage_base(in_place_t, _UArg&& __uarg)
: __value_(_VSTD::addressof(__uarg))
{
static_assert(__can_bind_reference<_UArg>(),
"Attempted to construct a reference element in tuple from a "
"possible temporary");
}
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void reset() noexcept { __value_ = nullptr; }
_LIBCPP_INLINE_VISIBILITY
constexpr bool has_value() const noexcept
{ return __value_ != nullptr; }
_LIBCPP_INLINE_VISIBILITY
constexpr value_type& __get() const& noexcept
{ return *__value_; }
_LIBCPP_INLINE_VISIBILITY
constexpr value_type&& __get() const&& noexcept
{ return _VSTD::forward<value_type>(*__value_); }
template <class _UArg>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct(_UArg&& __val)
{
_LIBCPP_ASSERT(!has_value(), "__construct called for engaged __optional_storage");
static_assert(__can_bind_reference<_UArg>(),
"Attempted to construct a reference element in tuple from a "
"possible temporary");
__value_ = _VSTD::addressof(__val);
}
template <class _That>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void __construct_from(_That&& __opt)
{
if (__opt.has_value())
__construct(_VSTD::forward<_That>(__opt).__get());
}
template <class _That>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void __assign_from(_That&& __opt)
{
if (has_value() == __opt.has_value())
{
if (has_value())
*__value_ = _VSTD::forward<_That>(__opt).__get();
}
else
{
if (has_value())
reset();
else
__construct(_VSTD::forward<_That>(__opt).__get());
}
}
};
template <class _Tp, bool = is_trivially_copy_constructible<_Tp>::value>
struct __optional_copy_base : __optional_storage_base<_Tp>
{
using __optional_storage_base<_Tp>::__optional_storage_base;
};
template <class _Tp>
struct __optional_copy_base<_Tp, false> : __optional_storage_base<_Tp>
{
using __optional_storage_base<_Tp>::__optional_storage_base;
_LIBCPP_INLINE_VISIBILITY
__optional_copy_base() = default;
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 __optional_copy_base(const __optional_copy_base& __opt)
{
this->__construct_from(__opt);
}
_LIBCPP_INLINE_VISIBILITY
__optional_copy_base(__optional_copy_base&&) = default;
_LIBCPP_INLINE_VISIBILITY
__optional_copy_base& operator=(const __optional_copy_base&) = default;
_LIBCPP_INLINE_VISIBILITY
__optional_copy_base& operator=(__optional_copy_base&&) = default;
};
template <class _Tp, bool = is_trivially_move_constructible<_Tp>::value>
struct __optional_move_base : __optional_copy_base<_Tp>
{
using __optional_copy_base<_Tp>::__optional_copy_base;
};
template <class _Tp>
struct __optional_move_base<_Tp, false> : __optional_copy_base<_Tp>
{
using value_type = _Tp;
using __optional_copy_base<_Tp>::__optional_copy_base;
_LIBCPP_INLINE_VISIBILITY
__optional_move_base() = default;
_LIBCPP_INLINE_VISIBILITY
__optional_move_base(const __optional_move_base&) = default;
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 __optional_move_base(__optional_move_base&& __opt)
noexcept(is_nothrow_move_constructible_v<value_type>)
{
this->__construct_from(_VSTD::move(__opt));
}
_LIBCPP_INLINE_VISIBILITY
__optional_move_base& operator=(const __optional_move_base&) = default;
_LIBCPP_INLINE_VISIBILITY
__optional_move_base& operator=(__optional_move_base&&) = default;
};
template <class _Tp, bool =
is_trivially_destructible<_Tp>::value &&
is_trivially_copy_constructible<_Tp>::value &&
is_trivially_copy_assignable<_Tp>::value>
struct __optional_copy_assign_base : __optional_move_base<_Tp>
{
using __optional_move_base<_Tp>::__optional_move_base;
};
template <class _Tp>
struct __optional_copy_assign_base<_Tp, false> : __optional_move_base<_Tp>
{
using __optional_move_base<_Tp>::__optional_move_base;
_LIBCPP_INLINE_VISIBILITY
__optional_copy_assign_base() = default;
_LIBCPP_INLINE_VISIBILITY
__optional_copy_assign_base(const __optional_copy_assign_base&) = default;
_LIBCPP_INLINE_VISIBILITY
__optional_copy_assign_base(__optional_copy_assign_base&&) = default;
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 __optional_copy_assign_base& operator=(const __optional_copy_assign_base& __opt)
{
this->__assign_from(__opt);
return *this;
}
_LIBCPP_INLINE_VISIBILITY
__optional_copy_assign_base& operator=(__optional_copy_assign_base&&) = default;
};
template <class _Tp, bool =
is_trivially_destructible<_Tp>::value &&
is_trivially_move_constructible<_Tp>::value &&
is_trivially_move_assignable<_Tp>::value>
struct __optional_move_assign_base : __optional_copy_assign_base<_Tp>
{
using __optional_copy_assign_base<_Tp>::__optional_copy_assign_base;
};
template <class _Tp>
struct __optional_move_assign_base<_Tp, false> : __optional_copy_assign_base<_Tp>
{
using value_type = _Tp;
using __optional_copy_assign_base<_Tp>::__optional_copy_assign_base;
_LIBCPP_INLINE_VISIBILITY
__optional_move_assign_base() = default;
_LIBCPP_INLINE_VISIBILITY
__optional_move_assign_base(const __optional_move_assign_base& __opt) = default;
_LIBCPP_INLINE_VISIBILITY
__optional_move_assign_base(__optional_move_assign_base&&) = default;
_LIBCPP_INLINE_VISIBILITY
__optional_move_assign_base& operator=(const __optional_move_assign_base&) = default;
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 __optional_move_assign_base& operator=(__optional_move_assign_base&& __opt)
noexcept(is_nothrow_move_assignable_v<value_type> &&
is_nothrow_move_constructible_v<value_type>)
{
this->__assign_from(_VSTD::move(__opt));
return *this;
}
};
template <class _Tp>
using __optional_sfinae_ctor_base_t = __sfinae_ctor_base<
is_copy_constructible<_Tp>::value,
is_move_constructible<_Tp>::value
>;
template <class _Tp>
using __optional_sfinae_assign_base_t = __sfinae_assign_base<
(is_copy_constructible<_Tp>::value && is_copy_assignable<_Tp>::value),
(is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value)
>;
template<class _Tp>
class optional;
template <class _Tp>
struct __is_std_optional : false_type {};
template <class _Tp> struct __is_std_optional<optional<_Tp>> : true_type {};
template <class _Tp>
class optional
: private __optional_move_assign_base<_Tp>
, private __optional_sfinae_ctor_base_t<_Tp>
, private __optional_sfinae_assign_base_t<_Tp>
{
using __base = __optional_move_assign_base<_Tp>;
public:
using value_type = _Tp;
private:
// Disable the reference extension using this static assert.
static_assert(!is_same_v<__uncvref_t<value_type>, in_place_t>,
"instantiation of optional with in_place_t is ill-formed");
static_assert(!is_same_v<__uncvref_t<value_type>, nullopt_t>,
"instantiation of optional with nullopt_t is ill-formed");
static_assert(!is_reference_v<value_type>,
"instantiation of optional with a reference type is ill-formed");
static_assert(is_destructible_v<value_type>,
"instantiation of optional with a non-destructible type is ill-formed");
static_assert(!is_array_v<value_type>,
"instantiation of optional with an array type is ill-formed");
// LWG2756: conditionally explicit conversion from _Up
struct _CheckOptionalArgsConstructor {
template <class _Up>
static constexpr bool __enable_implicit() {
return is_constructible_v<_Tp, _Up&&> &&
is_convertible_v<_Up&&, _Tp>;
}
template <class _Up>
static constexpr bool __enable_explicit() {
return is_constructible_v<_Tp, _Up&&> &&
!is_convertible_v<_Up&&, _Tp>;
}
};
template <class _Up>
using _CheckOptionalArgsCtor = _If<
_IsNotSame<__uncvref_t<_Up>, in_place_t>::value &&
_IsNotSame<__uncvref_t<_Up>, optional>::value,
_CheckOptionalArgsConstructor,
__check_tuple_constructor_fail
>;
template <class _QualUp>
struct _CheckOptionalLikeConstructor {
template <class _Up, class _Opt = optional<_Up>>
using __check_constructible_from_opt = _Or<
is_constructible<_Tp, _Opt&>,
is_constructible<_Tp, _Opt const&>,
is_constructible<_Tp, _Opt&&>,
is_constructible<_Tp, _Opt const&&>,
is_convertible<_Opt&, _Tp>,
is_convertible<_Opt const&, _Tp>,
is_convertible<_Opt&&, _Tp>,
is_convertible<_Opt const&&, _Tp>
>;
template <class _Up, class _Opt = optional<_Up>>
using __check_assignable_from_opt = _Or<
is_assignable<_Tp&, _Opt&>,
is_assignable<_Tp&, _Opt const&>,
is_assignable<_Tp&, _Opt&&>,
is_assignable<_Tp&, _Opt const&&>
>;
template <class _Up, class _QUp = _QualUp>
static constexpr bool __enable_implicit() {
return is_convertible<_QUp, _Tp>::value &&
!__check_constructible_from_opt<_Up>::value;
}
template <class _Up, class _QUp = _QualUp>
static constexpr bool __enable_explicit() {
return !is_convertible<_QUp, _Tp>::value &&
!__check_constructible_from_opt<_Up>::value;
}
template <class _Up, class _QUp = _QualUp>
static constexpr bool __enable_assign() {
// Construction and assignability of _QUp to _Tp has already been
// checked.
return !__check_constructible_from_opt<_Up>::value &&
!__check_assignable_from_opt<_Up>::value;
}
};
template <class _Up, class _QualUp>
using _CheckOptionalLikeCtor = _If<
_And<
_IsNotSame<_Up, _Tp>,
is_constructible<_Tp, _QualUp>
>::value,
_CheckOptionalLikeConstructor<_QualUp>,
__check_tuple_constructor_fail
>;
template <class _Up, class _QualUp>
using _CheckOptionalLikeAssign = _If<
_And<
_IsNotSame<_Up, _Tp>,
is_constructible<_Tp, _QualUp>,
is_assignable<_Tp&, _QualUp>
>::value,
_CheckOptionalLikeConstructor<_QualUp>,
__check_tuple_constructor_fail
>;
public:
_LIBCPP_INLINE_VISIBILITY constexpr optional() noexcept {}
_LIBCPP_INLINE_VISIBILITY constexpr optional(const optional&) = default;
_LIBCPP_INLINE_VISIBILITY constexpr optional(optional&&) = default;
_LIBCPP_INLINE_VISIBILITY constexpr optional(nullopt_t) noexcept {}
template <class _InPlaceT, class... _Args, class = enable_if_t<
_And<
_IsSame<_InPlaceT, in_place_t>,
is_constructible<value_type, _Args...>
>::value
>
>
_LIBCPP_INLINE_VISIBILITY
constexpr explicit optional(_InPlaceT, _Args&&... __args)
: __base(in_place, _VSTD::forward<_Args>(__args)...) {}
template <class _Up, class... _Args, class = enable_if_t<
is_constructible_v<value_type, initializer_list<_Up>&, _Args...>>
>
_LIBCPP_INLINE_VISIBILITY
constexpr explicit optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args)
: __base(in_place, __il, _VSTD::forward<_Args>(__args)...) {}
template <class _Up = value_type, enable_if_t<
_CheckOptionalArgsCtor<_Up>::template __enable_implicit<_Up>()
, int> = 0>
_LIBCPP_INLINE_VISIBILITY
constexpr optional(_Up&& __v)
: __base(in_place, _VSTD::forward<_Up>(__v)) {}
template <class _Up, enable_if_t<
_CheckOptionalArgsCtor<_Up>::template __enable_explicit<_Up>()
, int> = 0>
_LIBCPP_INLINE_VISIBILITY
constexpr explicit optional(_Up&& __v)
: __base(in_place, _VSTD::forward<_Up>(__v)) {}
// LWG2756: conditionally explicit conversion from const optional<_Up>&
template <class _Up, enable_if_t<
_CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_implicit<_Up>()
, int> = 0>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 optional(const optional<_Up>& __v)
{
this->__construct_from(__v);
}
template <class _Up, enable_if_t<
_CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_explicit<_Up>()
, int> = 0>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 explicit optional(const optional<_Up>& __v)
{
this->__construct_from(__v);
}
// LWG2756: conditionally explicit conversion from optional<_Up>&&
template <class _Up, enable_if_t<
_CheckOptionalLikeCtor<_Up, _Up &&>::template __enable_implicit<_Up>()
, int> = 0>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 optional(optional<_Up>&& __v)
{
this->__construct_from(_VSTD::move(__v));
}
template <class _Up, enable_if_t<
_CheckOptionalLikeCtor<_Up, _Up &&>::template __enable_explicit<_Up>()
, int> = 0>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 explicit optional(optional<_Up>&& __v)
{
this->__construct_from(_VSTD::move(__v));
}
#if _LIBCPP_STD_VER > 20
template<class _Fp, class... _Args>
_LIBCPP_HIDE_FROM_ABI
constexpr explicit optional(__optional_construct_from_invoke_tag, _Fp&& __f, _Args&&... __args)
: __base(__optional_construct_from_invoke_tag{}, _VSTD::forward<_Fp>(__f), _VSTD::forward<_Args>(__args)...) {
}
#endif
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 optional& operator=(nullopt_t) noexcept
{
reset();
return *this;
}
_LIBCPP_INLINE_VISIBILITY optional& operator=(const optional&) = default;
_LIBCPP_INLINE_VISIBILITY optional& operator=(optional&&) = default;
// LWG2756
template <class _Up = value_type,
class = enable_if_t<
_And<
_IsNotSame<__uncvref_t<_Up>, optional>,
_Or<
_IsNotSame<__uncvref_t<_Up>, value_type>,
_Not<is_scalar<value_type>>
>,
is_constructible<value_type, _Up>,
is_assignable<value_type&, _Up>
>::value>
>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 optional&
operator=(_Up&& __v)
{
if (this->has_value())
this->__get() = _VSTD::forward<_Up>(__v);
else
this->__construct(_VSTD::forward<_Up>(__v));
return *this;
}
// LWG2756
template <class _Up, enable_if_t<
_CheckOptionalLikeAssign<_Up, _Up const&>::template __enable_assign<_Up>()
, int> = 0>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 optional&
operator=(const optional<_Up>& __v)
{
this->__assign_from(__v);
return *this;
}
// LWG2756
template <class _Up, enable_if_t<
_CheckOptionalLikeCtor<_Up, _Up &&>::template __enable_assign<_Up>()
, int> = 0>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 optional&
operator=(optional<_Up>&& __v)
{
this->__assign_from(_VSTD::move(__v));
return *this;
}
template <class... _Args,
class = enable_if_t
<
is_constructible_v<value_type, _Args...>
>
>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp &
emplace(_Args&&... __args)
{
reset();
this->__construct(_VSTD::forward<_Args>(__args)...);
return this->__get();
}
template <class _Up, class... _Args,
class = enable_if_t
<
is_constructible_v<value_type, initializer_list<_Up>&, _Args...>
>
>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 _Tp &
emplace(initializer_list<_Up> __il, _Args&&... __args)
{
reset();
this->__construct(__il, _VSTD::forward<_Args>(__args)...);
return this->__get();
}
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_CONSTEXPR_AFTER_CXX17 void swap(optional& __opt)
noexcept(is_nothrow_move_constructible_v<value_type> &&
is_nothrow_swappable_v<value_type>)
{
if (this->has_value() == __opt.has_value())
{
using _VSTD::swap;
if (this->has_value())
swap(this->__get(), __opt.__get());
}
else
{
if (this->has_value())
{
__opt.__construct(_VSTD::move(this->__get()));
reset();
}
else
{
this->__construct(_VSTD::move(__opt.__get()));
__opt.reset();
}
}
}
_LIBCPP_INLINE_VISIBILITY
constexpr
add_pointer_t<value_type const>
operator->() const
{
_LIBCPP_ASSERT(this->has_value(), "optional operator-> called on a disengaged value");
return _VSTD::addressof(this->__get());
}
_LIBCPP_INLINE_VISIBILITY
constexpr
add_pointer_t<value_type>
operator->()
{
_LIBCPP_ASSERT(this->has_value(), "optional operator-> called on a disengaged value");
return _VSTD::addressof(this->__get());
}
_LIBCPP_INLINE_VISIBILITY
constexpr
const value_type&
operator*() const& noexcept
{
_LIBCPP_ASSERT(this->has_value(), "optional operator* called on a disengaged value");
return this->__get();
}
_LIBCPP_INLINE_VISIBILITY
constexpr
value_type&
operator*() & noexcept
{
_LIBCPP_ASSERT(this->has_value(), "optional operator* called on a disengaged value");
return this->__get();
}
_LIBCPP_INLINE_VISIBILITY
constexpr
value_type&&
operator*() && noexcept
{
_LIBCPP_ASSERT(this->has_value(), "optional operator* called on a disengaged value");
return _VSTD::move(this->__get());
}
_LIBCPP_INLINE_VISIBILITY
constexpr
const value_type&&
operator*() const&& noexcept
{
_LIBCPP_ASSERT(this->has_value(), "optional operator* called on a disengaged value");
return _VSTD::move(this->__get());
}
_LIBCPP_INLINE_VISIBILITY
constexpr explicit operator bool() const noexcept { return has_value(); }
using __base::has_value;
using __base::__get;
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr value_type const& value() const&
{
if (!this->has_value())
__throw_bad_optional_access();
return this->__get();
}
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr value_type& value() &
{
if (!this->has_value())
__throw_bad_optional_access();
return this->__get();
}
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr value_type&& value() &&
{
if (!this->has_value())
__throw_bad_optional_access();
return _VSTD::move(this->__get());
}
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr value_type const&& value() const&&
{
if (!this->has_value())
__throw_bad_optional_access();
return _VSTD::move(this->__get());
}
template <class _Up>
_LIBCPP_INLINE_VISIBILITY
constexpr value_type value_or(_Up&& __v) const&
{
static_assert(is_copy_constructible_v<value_type>,
"optional<T>::value_or: T must be copy constructible");
static_assert(is_convertible_v<_Up, value_type>,
"optional<T>::value_or: U must be convertible to T");
return this->has_value() ? this->__get() :
static_cast<value_type>(_VSTD::forward<_Up>(__v));
}
template <class _Up>
_LIBCPP_INLINE_VISIBILITY
constexpr value_type value_or(_Up&& __v) &&
{
static_assert(is_move_constructible_v<value_type>,
"optional<T>::value_or: T must be move constructible");
static_assert(is_convertible_v<_Up, value_type>,
"optional<T>::value_or: U must be convertible to T");
return this->has_value() ? _VSTD::move(this->__get()) :
static_cast<value_type>(_VSTD::forward<_Up>(__v));
}
#if _LIBCPP_STD_VER > 20
template<class _Func>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr auto and_then(_Func&& __f) & {
using _Up = invoke_result_t<_Func, value_type&>;
static_assert(__is_std_optional<remove_cvref_t<_Up>>::value,
"Result of f(value()) must be a specialization of std::optional");
if (*this)
return _VSTD::invoke(_VSTD::forward<_Func>(__f), value());
return remove_cvref_t<_Up>();
}
template<class _Func>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr auto and_then(_Func&& __f) const& {
using _Up = invoke_result_t<_Func, const value_type&>;
static_assert(__is_std_optional<remove_cvref_t<_Up>>::value,
"Result of f(value()) must be a specialization of std::optional");
if (*this)
return _VSTD::invoke(_VSTD::forward<_Func>(__f), value());
return remove_cvref_t<_Up>();
}
template<class _Func>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr auto and_then(_Func&& __f) && {
using _Up = invoke_result_t<_Func, value_type&&>;
static_assert(__is_std_optional<remove_cvref_t<_Up>>::value,
"Result of f(std::move(value())) must be a specialization of std::optional");
if (*this)
return _VSTD::invoke(_VSTD::forward<_Func>(__f), _VSTD::move(value()));
return remove_cvref_t<_Up>();
}
template<class _Func>
_LIBCPP_HIDE_FROM_ABI
constexpr auto and_then(_Func&& __f) const&& {
using _Up = invoke_result_t<_Func, const value_type&&>;
static_assert(__is_std_optional<remove_cvref_t<_Up>>::value,
"Result of f(std::move(value())) must be a specialization of std::optional");
if (*this)
return _VSTD::invoke(_VSTD::forward<_Func>(__f), _VSTD::move(value()));
return remove_cvref_t<_Up>();
}
template<class _Func>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr auto transform(_Func&& __f) & {
using _Up = remove_cv_t<invoke_result_t<_Func, value_type&>>;
static_assert(!is_array_v<_Up>, "Result of f(value()) should not be an Array");
static_assert(!is_same_v<_Up, in_place_t>,
"Result of f(value()) should not be std::in_place_t");
static_assert(!is_same_v<_Up, nullopt_t>,
"Result of f(value()) should not be std::nullopt_t");
static_assert(is_object_v<_Up>, "Result of f(value()) should be an object type");
if (*this)
return optional<_Up>(__optional_construct_from_invoke_tag{}, _VSTD::forward<_Func>(__f), value());
return optional<_Up>();
}
template<class _Func>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr auto transform(_Func&& __f) const& {
using _Up = remove_cv_t<invoke_result_t<_Func, const value_type&>>;
static_assert(!is_array_v<_Up>, "Result of f(value()) should not be an Array");
static_assert(!is_same_v<_Up, in_place_t>,
"Result of f(value()) should not be std::in_place_t");
static_assert(!is_same_v<_Up, nullopt_t>,
"Result of f(value()) should not be std::nullopt_t");
static_assert(is_object_v<_Up>, "Result of f(value()) should be an object type");
if (*this)
return optional<_Up>(__optional_construct_from_invoke_tag{}, _VSTD::forward<_Func>(__f), value());
return optional<_Up>();
}
template<class _Func>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr auto transform(_Func&& __f) && {
using _Up = remove_cv_t<invoke_result_t<_Func, value_type&&>>;
static_assert(!is_array_v<_Up>, "Result of f(std::move(value())) should not be an Array");
static_assert(!is_same_v<_Up, in_place_t>,
"Result of f(std::move(value())) should not be std::in_place_t");
static_assert(!is_same_v<_Up, nullopt_t>,
"Result of f(std::move(value())) should not be std::nullopt_t");
static_assert(is_object_v<_Up>, "Result of f(std::move(value())) should be an object type");
if (*this)
return optional<_Up>(__optional_construct_from_invoke_tag{}, _VSTD::forward<_Func>(__f), _VSTD::move(value()));
return optional<_Up>();
}
template<class _Func>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
constexpr auto transform(_Func&& __f) const&& {
using _Up = remove_cvref_t<invoke_result_t<_Func, const value_type&&>>;
static_assert(!is_array_v<_Up>, "Result of f(std::move(value())) should not be an Array");
static_assert(!is_same_v<_Up, in_place_t>,
"Result of f(std::move(value())) should not be std::in_place_t");
static_assert(!is_same_v<_Up, nullopt_t>,
"Result of f(std::move(value())) should not be std::nullopt_t");
static_assert(is_object_v<_Up>, "Result of f(std::move(value())) should be an object type");
if (*this)
return optional<_Up>(__optional_construct_from_invoke_tag{}, _VSTD::forward<_Func>(__f), _VSTD::move(value()));
return optional<_Up>();
}
template<invocable _Func>
_LIBCPP_HIDE_FROM_ABI
constexpr optional or_else(_Func&& __f) const& requires is_copy_constructible_v<value_type> {
static_assert(is_same_v<remove_cvref_t<invoke_result_t<_Func>>, optional>,
"Result of f() should be the same type as this optional");
if (*this)
return *this;
return _VSTD::forward<_Func>(__f)();
}
template<invocable _Func>
_LIBCPP_HIDE_FROM_ABI
constexpr optional or_else(_Func&& __f) && requires is_move_constructible_v<value_type> {
static_assert(is_same_v<remove_cvref_t<invoke_result_t<_Func>>, optional>,
"Result of f() should be the same type as this optional");
if (*this)
return _VSTD::move(*this);
return _VSTD::forward<_Func>(__f)();
}
#endif // _LIBCPP_STD_VER > 20
using __base::reset;
};
#if _LIBCPP_STD_VER >= 17
template<class _Tp>
optional(_Tp) -> optional<_Tp>;
#endif
// Comparisons between optionals
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() ==
declval<const _Up&>()), bool>,
bool
>
operator==(const optional<_Tp>& __x, const optional<_Up>& __y)
{
if (static_cast<bool>(__x) != static_cast<bool>(__y))
return false;
if (!static_cast<bool>(__x))
return true;
return *__x == *__y;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() !=
declval<const _Up&>()), bool>,
bool
>
operator!=(const optional<_Tp>& __x, const optional<_Up>& __y)
{
if (static_cast<bool>(__x) != static_cast<bool>(__y))
return true;
if (!static_cast<bool>(__x))
return false;
return *__x != *__y;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() <
declval<const _Up&>()), bool>,
bool
>
operator<(const optional<_Tp>& __x, const optional<_Up>& __y)
{
if (!static_cast<bool>(__y))
return false;
if (!static_cast<bool>(__x))
return true;
return *__x < *__y;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() >
declval<const _Up&>()), bool>,
bool
>
operator>(const optional<_Tp>& __x, const optional<_Up>& __y)
{
if (!static_cast<bool>(__x))
return false;
if (!static_cast<bool>(__y))
return true;
return *__x > *__y;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() <=
declval<const _Up&>()), bool>,
bool
>
operator<=(const optional<_Tp>& __x, const optional<_Up>& __y)
{
if (!static_cast<bool>(__x))
return true;
if (!static_cast<bool>(__y))
return false;
return *__x <= *__y;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() >=
declval<const _Up&>()), bool>,
bool
>
operator>=(const optional<_Tp>& __x, const optional<_Up>& __y)
{
if (!static_cast<bool>(__y))
return true;
if (!static_cast<bool>(__x))
return false;
return *__x >= *__y;
}
// Comparisons with nullopt
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator==(const optional<_Tp>& __x, nullopt_t) noexcept
{
return !static_cast<bool>(__x);
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator==(nullopt_t, const optional<_Tp>& __x) noexcept
{
return !static_cast<bool>(__x);
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator!=(const optional<_Tp>& __x, nullopt_t) noexcept
{
return static_cast<bool>(__x);
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator!=(nullopt_t, const optional<_Tp>& __x) noexcept
{
return static_cast<bool>(__x);
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator<(const optional<_Tp>&, nullopt_t) noexcept
{
return false;
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator<(nullopt_t, const optional<_Tp>& __x) noexcept
{
return static_cast<bool>(__x);
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator<=(const optional<_Tp>& __x, nullopt_t) noexcept
{
return !static_cast<bool>(__x);
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator<=(nullopt_t, const optional<_Tp>&) noexcept
{
return true;
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator>(const optional<_Tp>& __x, nullopt_t) noexcept
{
return static_cast<bool>(__x);
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator>(nullopt_t, const optional<_Tp>&) noexcept
{
return false;
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator>=(const optional<_Tp>&, nullopt_t) noexcept
{
return true;
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
bool
operator>=(nullopt_t, const optional<_Tp>& __x) noexcept
{
return !static_cast<bool>(__x);
}
// Comparisons with T
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() ==
declval<const _Up&>()), bool>,
bool
>
operator==(const optional<_Tp>& __x, const _Up& __v)
{
return static_cast<bool>(__x) ? *__x == __v : false;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() ==
declval<const _Up&>()), bool>,
bool
>
operator==(const _Tp& __v, const optional<_Up>& __x)
{
return static_cast<bool>(__x) ? __v == *__x : false;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() !=
declval<const _Up&>()), bool>,
bool
>
operator!=(const optional<_Tp>& __x, const _Up& __v)
{
return static_cast<bool>(__x) ? *__x != __v : true;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() !=
declval<const _Up&>()), bool>,
bool
>
operator!=(const _Tp& __v, const optional<_Up>& __x)
{
return static_cast<bool>(__x) ? __v != *__x : true;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() <
declval<const _Up&>()), bool>,
bool
>
operator<(const optional<_Tp>& __x, const _Up& __v)
{
return static_cast<bool>(__x) ? *__x < __v : true;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() <
declval<const _Up&>()), bool>,
bool
>
operator<(const _Tp& __v, const optional<_Up>& __x)
{
return static_cast<bool>(__x) ? __v < *__x : false;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() <=
declval<const _Up&>()), bool>,
bool
>
operator<=(const optional<_Tp>& __x, const _Up& __v)
{
return static_cast<bool>(__x) ? *__x <= __v : true;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() <=
declval<const _Up&>()), bool>,
bool
>
operator<=(const _Tp& __v, const optional<_Up>& __x)
{
return static_cast<bool>(__x) ? __v <= *__x : false;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() >
declval<const _Up&>()), bool>,
bool
>
operator>(const optional<_Tp>& __x, const _Up& __v)
{
return static_cast<bool>(__x) ? *__x > __v : false;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() >
declval<const _Up&>()), bool>,
bool
>
operator>(const _Tp& __v, const optional<_Up>& __x)
{
return static_cast<bool>(__x) ? __v > *__x : true;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() >=
declval<const _Up&>()), bool>,
bool
>
operator>=(const optional<_Tp>& __x, const _Up& __v)
{
return static_cast<bool>(__x) ? *__x >= __v : false;
}
template <class _Tp, class _Up>
_LIBCPP_INLINE_VISIBILITY constexpr
enable_if_t<
is_convertible_v<decltype(declval<const _Tp&>() >=
declval<const _Up&>()), bool>,
bool
>
operator>=(const _Tp& __v, const optional<_Up>& __x)
{
return static_cast<bool>(__x) ? __v >= *__x : true;
}
template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
enable_if_t<
is_move_constructible_v<_Tp> && is_swappable_v<_Tp>,
void
>
swap(optional<_Tp>& __x, optional<_Tp>& __y) noexcept(noexcept(__x.swap(__y)))
{
__x.swap(__y);
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr
optional<decay_t<_Tp>> make_optional(_Tp&& __v)
{
return optional<decay_t<_Tp>>(_VSTD::forward<_Tp>(__v));
}
template <class _Tp, class... _Args>
_LIBCPP_INLINE_VISIBILITY constexpr
optional<_Tp> make_optional(_Args&&... __args)
{
return optional<_Tp>(in_place, _VSTD::forward<_Args>(__args)...);
}
template <class _Tp, class _Up, class... _Args>
_LIBCPP_INLINE_VISIBILITY constexpr
optional<_Tp> make_optional(initializer_list<_Up> __il, _Args&&... __args)
{
return optional<_Tp>(in_place, __il, _VSTD::forward<_Args>(__args)...);
}
template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS hash<
__enable_hash_helper<optional<_Tp>, remove_const_t<_Tp>>
>
{
#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_BINDER_TYPEDEFS)
_LIBCPP_DEPRECATED_IN_CXX17 typedef optional<_Tp> argument_type;
_LIBCPP_DEPRECATED_IN_CXX17 typedef size_t result_type;
#endif
_LIBCPP_INLINE_VISIBILITY
size_t operator()(const optional<_Tp>& __opt) const
{
return static_cast<bool>(__opt) ? hash<remove_const_t<_Tp>>()(*__opt) : 0;
}
};
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_STD_VER > 14
#endif // _LIBCPP_OPTIONAL
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