e2ce9436fb
2014-04-25 Lars Gullik Bjønnes <larsbj@gullik.org> PR libstdc++/60710 * include/experimental/optional (operator!=): Implement in terms of operator==. * testsuite/experimental/optional/relops/1.cc: Remove operator!=. * testsuite/experimental/optional/relops/2.cc: Likewise. * testsuite/experimental/optional/relops/3.cc: Likewise. * testsuite/experimental/optional/relops/4.cc: Likewise. * testsuite/experimental/optional/relops/5.cc: Likewise. * testsuite/experimental/optional/relops/6.cc: Likewise. From-SVN: r209810
824 lines
23 KiB
C++
824 lines
23 KiB
C++
// <optional> -*- C++ -*-
|
|
|
|
// Copyright (C) 2013-2014 Free Software Foundation, Inc.
|
|
//
|
|
// This file is part of the GNU ISO C++ Library. This library is free
|
|
// software; you can redistribute it and/or modify it under the
|
|
// terms of the GNU General Public License as published by the
|
|
// Free Software Foundation; either version 3, or (at your option)
|
|
// any later version.
|
|
|
|
// This library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
|
|
// Under Section 7 of GPL version 3, you are granted additional
|
|
// permissions described in the GCC Runtime Library Exception, version
|
|
// 3.1, as published by the Free Software Foundation.
|
|
|
|
// You should have received a copy of the GNU General Public License and
|
|
// a copy of the GCC Runtime Library Exception along with this program;
|
|
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
|
// <http://www.gnu.org/licenses/>.
|
|
|
|
/** @file experimental/optional
|
|
* This is a TS C++ Library header.
|
|
*/
|
|
|
|
#ifndef _GLIBCXX_EXPERIMENTAL_OPTIONAL
|
|
#define _GLIBCXX_EXPERIMENTAL_OPTIONAL 1
|
|
|
|
/**
|
|
* @defgroup experimental Experimental
|
|
*
|
|
* Components specified by various Technical Specifications.
|
|
*/
|
|
|
|
#if __cplusplus <= 201103L
|
|
# include <bits/c++14_warning.h>
|
|
#else
|
|
|
|
#include <utility>
|
|
#include <type_traits>
|
|
#include <stdexcept>
|
|
#include <new>
|
|
#include <initializer_list>
|
|
#include <bits/functexcept.h>
|
|
#include <bits/functional_hash.h>
|
|
#include <bits/enable_special_members.h>
|
|
|
|
namespace std _GLIBCXX_VISIBILITY(default)
|
|
{
|
|
namespace experimental
|
|
{
|
|
_GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|
|
|
/**
|
|
* @defgroup optional Optional values
|
|
* @ingroup experimental
|
|
*
|
|
* Class template for optional values and surrounding facilities, as
|
|
* described in n3793 "A proposal to add a utility class to represent
|
|
* optional objects (Revision 5)".
|
|
*
|
|
* @{
|
|
*/
|
|
|
|
// All subsequent [X.Y.n] references are against n3793.
|
|
|
|
// [X.Y.4]
|
|
template<typename _Tp>
|
|
class optional;
|
|
|
|
// [X.Y.5]
|
|
/// Tag type for in-place construction.
|
|
struct in_place_t { };
|
|
|
|
/// Tag for in-place construction.
|
|
constexpr in_place_t in_place { };
|
|
|
|
// [X.Y.6]
|
|
/// Tag type to disengage optional objects.
|
|
struct nullopt_t
|
|
{
|
|
// Do not user-declare default constructor at all for
|
|
// optional_value = {} syntax to work.
|
|
// nullopt_t() = delete;
|
|
|
|
// Used for constructing nullopt.
|
|
enum class _Construct { _Token };
|
|
|
|
// Must be constexpr for nullopt_t to be literal.
|
|
explicit constexpr nullopt_t(_Construct) { }
|
|
};
|
|
|
|
// [X.Y.6]
|
|
/// Tag to disengage optional objects.
|
|
constexpr nullopt_t nullopt { nullopt_t::_Construct::_Token };
|
|
|
|
// [X.Y.7]
|
|
/**
|
|
* @brief Exception class thrown when a disengaged optional object is
|
|
* dereferenced.
|
|
* @ingroup exceptions
|
|
*/
|
|
class bad_optional_access : public logic_error
|
|
{
|
|
public:
|
|
// XXX Should not be inline
|
|
explicit bad_optional_access(const string& __arg) : logic_error(__arg) { }
|
|
|
|
explicit bad_optional_access(const char* __arg) : logic_error(__arg) { }
|
|
|
|
virtual ~bad_optional_access() noexcept = default;
|
|
};
|
|
|
|
void
|
|
__throw_bad_optional_access(const char*)
|
|
__attribute__((__noreturn__));
|
|
|
|
// XXX Does not belong here.
|
|
inline void
|
|
__throw_bad_optional_access(const char* __s)
|
|
{ _GLIBCXX_THROW_OR_ABORT(bad_optional_access(__s)); }
|
|
|
|
template<typename _Tp, typename _Sfinae = void>
|
|
struct _Has_addressof_impl : std::false_type { };
|
|
|
|
template<typename _Tp>
|
|
struct _Has_addressof_impl<_Tp,
|
|
decltype( std::declval<const _Tp&>().operator&(), void() )>
|
|
: std::true_type { };
|
|
|
|
/**
|
|
* @brief Trait that detects the presence of an overloaded unary operator&.
|
|
*
|
|
* Practically speaking this detects the presence of such an operator when
|
|
* called on a const-qualified lvalue (i.e.
|
|
* declval<_Tp * const&>().operator&()).
|
|
*/
|
|
template<typename _Tp>
|
|
struct _Has_addressof : _Has_addressof_impl<_Tp>::type { };
|
|
|
|
/**
|
|
* @brief An overload that attempts to take the address of an lvalue as a
|
|
* constant expression. Falls back to __addressof in the presence of an
|
|
* overloaded addressof operator (unary operator&), in which case the call
|
|
* will not be a constant expression.
|
|
*/
|
|
template<typename _Tp, typename enable_if<!_Has_addressof<_Tp>::value,
|
|
int>::type...>
|
|
constexpr _Tp* __constexpr_addressof(_Tp& __t)
|
|
{ return &__t; }
|
|
|
|
/**
|
|
* @brief Fallback overload that defers to __addressof.
|
|
*/
|
|
template<typename _Tp, typename enable_if<_Has_addressof<_Tp>::value,
|
|
int>::type...>
|
|
inline _Tp* __constexpr_addressof(_Tp& __t)
|
|
{ return std::__addressof(__t); }
|
|
|
|
/**
|
|
* @brief Class template that holds the necessary state for @ref optional
|
|
* and that has the responsibility for construction and the special members.
|
|
*
|
|
* Such a separate base class template is necessary in order to
|
|
* conditionally enable the special members (e.g. copy/move constructors).
|
|
* Note that this means that @ref _Optional_base implements the
|
|
* functionality for copy and move assignment, but not for converting
|
|
* assignment.
|
|
*
|
|
* @see optional, _Enable_special_members
|
|
*/
|
|
template<typename _Tp, bool _ShouldProvideDestructor =
|
|
!is_trivially_destructible<_Tp>::value>
|
|
class _Optional_base
|
|
{
|
|
private:
|
|
// Remove const to avoid prohibition of reusing object storage for
|
|
// const-qualified types in [3.8/9]. This is strictly internal
|
|
// and even optional itself is oblivious to it.
|
|
using _Stored_type = typename remove_const<_Tp>::type;
|
|
|
|
public:
|
|
// [X.Y.4.1] Constructors.
|
|
|
|
// Constructors for disengaged optionals.
|
|
constexpr _Optional_base() noexcept
|
|
: _M_empty{} { }
|
|
|
|
constexpr _Optional_base(nullopt_t) noexcept
|
|
: _Optional_base{} { }
|
|
|
|
// Constructors for engaged optionals.
|
|
constexpr _Optional_base(const _Tp& __t)
|
|
: _M_payload(__t), _M_engaged(true) { }
|
|
|
|
constexpr _Optional_base(_Tp&& __t)
|
|
: _M_payload(std::move(__t)), _M_engaged(true) { }
|
|
|
|
template<typename... _Args>
|
|
constexpr explicit _Optional_base(in_place_t, _Args&&... __args)
|
|
: _M_payload(std::forward<_Args>(__args)...), _M_engaged(true) { }
|
|
|
|
template<typename _Up, typename... _Args,
|
|
typename enable_if<is_constructible<_Tp,
|
|
initializer_list<_Up>&,
|
|
_Args&&...>::value,
|
|
int>::type...>
|
|
constexpr explicit _Optional_base(in_place_t,
|
|
initializer_list<_Up> __il,
|
|
_Args&&... __args)
|
|
: _M_payload(__il, std::forward<_Args>(__args)...),
|
|
_M_engaged(true) { }
|
|
|
|
// Copy and move constructors.
|
|
_Optional_base(const _Optional_base& __other)
|
|
{
|
|
if (__other._M_engaged)
|
|
this->_M_construct(__other._M_get());
|
|
}
|
|
|
|
_Optional_base(_Optional_base&& __other)
|
|
noexcept(is_nothrow_move_constructible<_Tp>())
|
|
{
|
|
if (__other._M_engaged)
|
|
this->_M_construct(std::move(__other._M_get()));
|
|
}
|
|
|
|
// [X.Y.4.3] (partly) Assignment.
|
|
_Optional_base&
|
|
operator=(const _Optional_base& __other)
|
|
{
|
|
if (this->_M_engaged && __other._M_engaged)
|
|
this->_M_get() = __other._M_get();
|
|
else
|
|
{
|
|
if (__other._M_engaged)
|
|
this->_M_construct(__other._M_get());
|
|
else
|
|
this->_M_reset();
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
_Optional_base&
|
|
operator=(_Optional_base&& __other)
|
|
noexcept(__and_<is_nothrow_move_constructible<_Tp>,
|
|
is_nothrow_move_assignable<_Tp>>())
|
|
{
|
|
if (this->_M_engaged && __other._M_engaged)
|
|
this->_M_get() = std::move(__other._M_get());
|
|
else
|
|
{
|
|
if (__other._M_engaged)
|
|
this->_M_construct(std::move(__other._M_get()));
|
|
else
|
|
this->_M_reset();
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
// [X.Y.4.2] Destructor.
|
|
~_Optional_base()
|
|
{
|
|
if (this->_M_engaged)
|
|
this->_M_payload.~_Stored_type();
|
|
}
|
|
|
|
// The following functionality is also needed by optional, hence the
|
|
// protected accessibility.
|
|
protected:
|
|
constexpr bool _M_is_engaged() const noexcept
|
|
{ return this->_M_engaged; }
|
|
|
|
// The _M_get operations have _M_engaged as a precondition.
|
|
_Tp&
|
|
_M_get() noexcept
|
|
{ return _M_payload; }
|
|
|
|
constexpr const _Tp&
|
|
_M_get() const noexcept
|
|
{ return _M_payload; }
|
|
|
|
// The _M_construct operation has !_M_engaged as a precondition
|
|
// while _M_destruct has _M_engaged as a precondition.
|
|
template<typename... _Args>
|
|
void
|
|
_M_construct(_Args&&... __args)
|
|
noexcept(is_nothrow_constructible<_Stored_type, _Args...>())
|
|
{
|
|
::new (std::__addressof(this->_M_payload))
|
|
_Stored_type(std::forward<_Args>(__args)...);
|
|
this->_M_engaged = true;
|
|
}
|
|
|
|
void
|
|
_M_destruct()
|
|
{
|
|
this->_M_engaged = false;
|
|
this->_M_payload.~_Stored_type();
|
|
}
|
|
|
|
// _M_reset is a 'safe' operation with no precondition.
|
|
void
|
|
_M_reset()
|
|
{
|
|
if (this->_M_engaged)
|
|
this->_M_destruct();
|
|
}
|
|
|
|
private:
|
|
struct _Empty_byte { };
|
|
union {
|
|
_Empty_byte _M_empty;
|
|
_Stored_type _M_payload;
|
|
};
|
|
bool _M_engaged = false;
|
|
};
|
|
|
|
/// Partial specialization that is exactly identical to the primary template
|
|
/// save for not providing a destructor, to fulfill triviality requirements.
|
|
template<typename _Tp>
|
|
class _Optional_base<_Tp, false>
|
|
{
|
|
private:
|
|
using _Stored_type = typename remove_const<_Tp>::type;
|
|
|
|
public:
|
|
constexpr _Optional_base() noexcept
|
|
: _M_empty{} { }
|
|
|
|
constexpr _Optional_base(nullopt_t) noexcept
|
|
: _Optional_base{} { }
|
|
|
|
constexpr _Optional_base(const _Tp& __t)
|
|
: _M_payload(__t), _M_engaged(true) { }
|
|
|
|
constexpr _Optional_base(_Tp&& __t)
|
|
: _M_payload(std::move(__t)), _M_engaged(true) { }
|
|
|
|
template<typename... _Args>
|
|
constexpr explicit _Optional_base(in_place_t, _Args&&... __args)
|
|
: _M_payload(std::forward<_Args>(__args)...), _M_engaged(true) { }
|
|
|
|
template<typename _Up, typename... _Args,
|
|
typename enable_if<is_constructible<_Tp,
|
|
initializer_list<_Up>&,
|
|
_Args&&...>::value,
|
|
int>::type...>
|
|
constexpr explicit _Optional_base(in_place_t,
|
|
initializer_list<_Up> __il,
|
|
_Args&&... __args)
|
|
: _M_payload(__il, std::forward<_Args>(__args)...),
|
|
_M_engaged(true) { }
|
|
|
|
_Optional_base(const _Optional_base& __other)
|
|
{
|
|
if (__other._M_engaged)
|
|
this->_M_construct(__other._M_get());
|
|
}
|
|
|
|
_Optional_base(_Optional_base&& __other)
|
|
noexcept(is_nothrow_move_constructible<_Tp>())
|
|
{
|
|
if (__other._M_engaged)
|
|
this->_M_construct(std::move(__other._M_get()));
|
|
}
|
|
|
|
_Optional_base&
|
|
operator=(const _Optional_base& __other)
|
|
{
|
|
if (this->_M_engaged && __other._M_engaged)
|
|
this->_M_get() = __other._M_get();
|
|
else
|
|
{
|
|
if (__other._M_engaged)
|
|
this->_M_construct(__other._M_get());
|
|
else
|
|
this->_M_reset();
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
_Optional_base&
|
|
operator=(_Optional_base&& __other)
|
|
noexcept(__and_<is_nothrow_move_constructible<_Tp>,
|
|
is_nothrow_move_assignable<_Tp>>())
|
|
{
|
|
if (this->_M_engaged && __other._M_engaged)
|
|
this->_M_get() = std::move(__other._M_get());
|
|
else
|
|
{
|
|
if (__other._M_engaged)
|
|
this->_M_construct(std::move(__other._M_get()));
|
|
else
|
|
this->_M_reset();
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
// Sole difference
|
|
// ~_Optional_base() noexcept = default;
|
|
|
|
protected:
|
|
constexpr bool _M_is_engaged() const noexcept
|
|
{ return this->_M_engaged; }
|
|
|
|
_Tp&
|
|
_M_get() noexcept
|
|
{ return _M_payload; }
|
|
|
|
constexpr const _Tp&
|
|
_M_get() const noexcept
|
|
{ return _M_payload; }
|
|
|
|
template<typename... _Args>
|
|
void
|
|
_M_construct(_Args&&... __args)
|
|
noexcept(is_nothrow_constructible<_Stored_type, _Args...>())
|
|
{
|
|
::new (std::__addressof(this->_M_payload))
|
|
_Stored_type(std::forward<_Args>(__args)...);
|
|
this->_M_engaged = true;
|
|
}
|
|
|
|
void
|
|
_M_destruct()
|
|
{
|
|
this->_M_engaged = false;
|
|
this->_M_payload.~_Stored_type();
|
|
}
|
|
|
|
void
|
|
_M_reset()
|
|
{
|
|
if (this->_M_engaged)
|
|
this->_M_destruct();
|
|
}
|
|
|
|
private:
|
|
struct _Empty_byte { };
|
|
union
|
|
{
|
|
_Empty_byte _M_empty;
|
|
_Stored_type _M_payload;
|
|
};
|
|
bool _M_engaged = false;
|
|
};
|
|
|
|
/**
|
|
* @brief Class template for optional values.
|
|
*/
|
|
template<typename _Tp>
|
|
class optional
|
|
: private _Optional_base<_Tp>,
|
|
private _Enable_copy_move<
|
|
// Copy constructor.
|
|
is_copy_constructible<_Tp>::value,
|
|
// Copy assignment.
|
|
__and_<is_copy_constructible<_Tp>, is_copy_assignable<_Tp>>::value,
|
|
// Move constructor.
|
|
is_move_constructible<_Tp>::value,
|
|
// Move assignment.
|
|
__and_<is_move_constructible<_Tp>, is_move_assignable<_Tp>>::value,
|
|
// Unique tag type.
|
|
optional<_Tp>>
|
|
{
|
|
static_assert(__and_<__not_<is_same<typename remove_cv<_Tp>::type,
|
|
nullopt_t>>,
|
|
__not_<is_same<typename remove_cv<_Tp>::type,
|
|
in_place_t>>,
|
|
__not_<is_reference<_Tp>>>(),
|
|
"Invalid instantiation of optional<T>");
|
|
|
|
private:
|
|
using _Base = _Optional_base<_Tp>;
|
|
|
|
public:
|
|
using value_type = _Tp;
|
|
|
|
// _Optional_base has the responsibility for construction.
|
|
using _Base::_Base;
|
|
|
|
// [X.Y.4.3] (partly) Assignment.
|
|
optional&
|
|
operator=(nullopt_t) noexcept
|
|
{
|
|
this->_M_reset();
|
|
return *this;
|
|
}
|
|
|
|
template<typename _Up>
|
|
typename enable_if<
|
|
is_same<_Tp, typename decay<_Up>::type>::value,
|
|
optional&
|
|
>::type
|
|
operator=(_Up&& __u)
|
|
{
|
|
static_assert(__and_<is_constructible<_Tp, _Up>,
|
|
is_assignable<_Tp&, _Up>>(),
|
|
"Cannot assign to value type from argument");
|
|
|
|
if (this->_M_is_engaged())
|
|
this->_M_get() = std::forward<_Up>(__u);
|
|
else
|
|
this->_M_construct(std::forward<_Up>(__u));
|
|
|
|
return *this;
|
|
}
|
|
|
|
template<typename... _Args>
|
|
void
|
|
emplace(_Args&&... __args)
|
|
{
|
|
static_assert(is_constructible<_Tp, _Args&&...>(),
|
|
"Cannot emplace value type from arguments");
|
|
|
|
this->_M_reset();
|
|
this->_M_construct(std::forward<_Args>(__args)...);
|
|
}
|
|
|
|
template<typename _Up, typename... _Args>
|
|
typename enable_if<
|
|
is_constructible<_Tp,
|
|
initializer_list<_Up>&,
|
|
_Args&&...>::value
|
|
>::type
|
|
emplace(initializer_list<_Up> __il, _Args&&... __args)
|
|
{
|
|
this->_M_reset();
|
|
this->_M_construct(__il, std::forward<_Args>(__args)...);
|
|
}
|
|
|
|
// [X.Y.4.2] Destructor is implicit, implemented in _Optional_base.
|
|
|
|
// [X.Y.4.4] Swap.
|
|
void
|
|
swap(optional& __other)
|
|
noexcept(is_nothrow_move_constructible<_Tp>()
|
|
&& noexcept(swap(declval<_Tp&>(), declval<_Tp&>())))
|
|
{
|
|
using std::swap;
|
|
|
|
if (this->_M_is_engaged() && __other._M_is_engaged())
|
|
swap(this->_M_get(), __other._M_get());
|
|
else if (this->_M_is_engaged())
|
|
{
|
|
__other._M_construct(std::move(this->_M_get()));
|
|
this->_M_destruct();
|
|
}
|
|
else if (__other._M_is_engaged())
|
|
{
|
|
this->_M_construct(std::move(__other._M_get()));
|
|
__other._M_destruct();
|
|
}
|
|
}
|
|
|
|
// [X.Y.4.5] Observers.
|
|
constexpr const _Tp*
|
|
operator->() const
|
|
{ return __constexpr_addressof(this->_M_get()); }
|
|
|
|
_Tp*
|
|
operator->()
|
|
{ return std::__addressof(this->_M_get()); }
|
|
|
|
constexpr const _Tp&
|
|
operator*() const
|
|
{ return this->_M_get(); }
|
|
|
|
_Tp&
|
|
operator*()
|
|
{ return this->_M_get(); }
|
|
|
|
constexpr explicit operator bool() const noexcept
|
|
{ return this->_M_is_engaged(); }
|
|
|
|
constexpr const _Tp&
|
|
value() const
|
|
{
|
|
return this->_M_is_engaged()
|
|
? this->_M_get()
|
|
: (__throw_bad_optional_access("Attempt to access value of a "
|
|
"disengaged optional object"),
|
|
this->_M_get());
|
|
}
|
|
|
|
_Tp&
|
|
value()
|
|
{
|
|
if (this->_M_is_engaged())
|
|
return this->_M_get();
|
|
|
|
__throw_bad_optional_access("Attempt to access value of a "
|
|
"disengaged optional object");
|
|
}
|
|
|
|
template<typename _Up>
|
|
constexpr _Tp
|
|
value_or(_Up&& __u) const&
|
|
{
|
|
static_assert(__and_<is_copy_constructible<_Tp>,
|
|
is_convertible<_Up&&, _Tp>>(),
|
|
"Cannot return value");
|
|
|
|
return this->_M_is_engaged()
|
|
? this->_M_get()
|
|
: static_cast<_Tp>(std::forward<_Up>(__u));
|
|
}
|
|
|
|
template<typename _Up>
|
|
_Tp
|
|
value_or(_Up&& __u) &&
|
|
{
|
|
static_assert(__and_<is_move_constructible<_Tp>,
|
|
is_convertible<_Up&&, _Tp>>(),
|
|
"Cannot return value" );
|
|
|
|
return this->_M_is_engaged()
|
|
? std::move(this->_M_get())
|
|
: static_cast<_Tp>(std::forward<_Up>(__u));
|
|
}
|
|
};
|
|
|
|
// [X.Y.8] Comparisons between optional values.
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator==(const optional<_Tp>& __lhs, const optional<_Tp>& __rhs)
|
|
{
|
|
return static_cast<bool>(__lhs) == static_cast<bool>(__rhs)
|
|
&& (!__lhs || *__lhs == *__rhs);
|
|
}
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator!=(const optional<_Tp>& __lhs, const optional<_Tp>& __rhs)
|
|
{ return !(__lhs == __rhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<(const optional<_Tp>& __lhs, const optional<_Tp>& __rhs)
|
|
{
|
|
return static_cast<bool>(__rhs) && (!__lhs || *__lhs < *__rhs);
|
|
}
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>(const optional<_Tp>& __lhs, const optional<_Tp>& __rhs)
|
|
{ return __rhs < __lhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<=(const optional<_Tp>& __lhs, const optional<_Tp>& __rhs)
|
|
{ return !(__rhs < __lhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>=(const optional<_Tp>& __lhs, const optional<_Tp>& __rhs)
|
|
{ return !(__lhs < __rhs); }
|
|
|
|
// [X.Y.9] Comparisons with nullopt.
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator==(const optional<_Tp>& __lhs, nullopt_t) noexcept
|
|
{ return !__lhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator==(nullopt_t, const optional<_Tp>& __rhs) noexcept
|
|
{ return !__rhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator!=(const optional<_Tp>& __lhs, nullopt_t) noexcept
|
|
{ return static_cast<bool>(__lhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator!=(nullopt_t, const optional<_Tp>& __rhs) noexcept
|
|
{ return static_cast<bool>(__rhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<(const optional<_Tp>& /* __lhs */, nullopt_t) noexcept
|
|
{ return false; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<(nullopt_t, const optional<_Tp>& __rhs) noexcept
|
|
{ return static_cast<bool>(__rhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>(const optional<_Tp>& __lhs, nullopt_t) noexcept
|
|
{ return static_cast<bool>(__lhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>(nullopt_t, const optional<_Tp>& /* __rhs */) noexcept
|
|
{ return false; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<=(const optional<_Tp>& __lhs, nullopt_t) noexcept
|
|
{ return !__lhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<=(nullopt_t, const optional<_Tp>& /* __rhs */) noexcept
|
|
{ return true; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>=(const optional<_Tp>& /* __lhs */, nullopt_t) noexcept
|
|
{ return true; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>=(nullopt_t, const optional<_Tp>& __rhs) noexcept
|
|
{ return !__rhs; }
|
|
|
|
// [X.Y.10] Comparisons with value type.
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator==(const optional<_Tp>& __lhs, const _Tp& __rhs)
|
|
{ return __lhs && *__lhs == __rhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator==(const _Tp& __lhs, const optional<_Tp>& __rhs)
|
|
{ return __rhs && __lhs == *__rhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator!=(const optional<_Tp>& __lhs, _Tp const& __rhs)
|
|
{ return !__lhs || !(*__lhs == __rhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator!=(const _Tp& __lhs, const optional<_Tp>& __rhs)
|
|
{ return !__rhs || !(__lhs == *__rhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<(const optional<_Tp>& __lhs, const _Tp& __rhs)
|
|
{ return !__lhs || *__lhs < __rhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<(const _Tp& __lhs, const optional<_Tp>& __rhs)
|
|
{ return __rhs && __lhs < *__rhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>(const optional<_Tp>& __lhs, const _Tp& __rhs)
|
|
{ return __lhs && __rhs < *__lhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>(const _Tp& __lhs, const optional<_Tp>& __rhs)
|
|
{ return !__rhs || *__rhs < __lhs; }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<=(const optional<_Tp>& __lhs, const _Tp& __rhs)
|
|
{ return !__lhs || !(__rhs < *__lhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator<=(const _Tp& __lhs, const optional<_Tp>& __rhs)
|
|
{ return __rhs && !(*__rhs < __lhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>=(const optional<_Tp>& __lhs, const _Tp& __rhs)
|
|
{ return __lhs && !(*__lhs < __rhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr bool
|
|
operator>=(const _Tp& __lhs, const optional<_Tp>& __rhs)
|
|
{ return !__rhs || !(__lhs < *__rhs); }
|
|
|
|
// [X.Y.11]
|
|
template<typename _Tp>
|
|
inline void
|
|
swap(optional<_Tp>& __lhs, optional<_Tp>& __rhs)
|
|
noexcept(noexcept(__lhs.swap(__rhs)))
|
|
{ __lhs.swap(__rhs); }
|
|
|
|
template<typename _Tp>
|
|
constexpr optional<typename decay<_Tp>::type>
|
|
make_optional(_Tp&& __t)
|
|
{ return optional<typename decay<_Tp>::type> { std::forward<_Tp>(__t) }; }
|
|
|
|
// @} group optional
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
}
|
|
|
|
// [X.Y.12]
|
|
template<typename _Tp>
|
|
struct hash<experimental::optional<_Tp>>
|
|
{
|
|
using result_type = size_t;
|
|
using argument_type = experimental::optional<_Tp>;
|
|
|
|
size_t
|
|
operator()(const experimental::optional<_Tp>& __t) const
|
|
noexcept(noexcept(hash<_Tp> {}(*__t)))
|
|
{
|
|
// We pick an arbitrary hash for disengaged optionals which hopefully
|
|
// usual values of _Tp won't typically hash to.
|
|
constexpr size_t __magic_disengaged_hash = static_cast<size_t>(-3333);
|
|
return __t ? hash<_Tp> {}(*__t) : __magic_disengaged_hash;
|
|
}
|
|
};
|
|
}
|
|
|
|
#endif // C++14
|
|
|
|
#endif // _GLIBCXX_EXPERIMENTAL_OPTIONAL
|