[v3 PATCH] Use constexpr addressof in optional, SFINAE housekeeping for any, optional and tuple.
Ville Voutilainen
ville.voutilainen@gmail.com
Wed Oct 26 17:10:00 GMT 2016
Tested on Linux-PPC64.
2016-10-26 Ville Voutilainen <ville.voutilainen@gmail.com>
Use constexpr addressof in optional, SFINAE housekeeping
for any, optional and tuple.
* include/std/any (__do_emplace(_Args&&...)): New.
(__do_emplace(initializer_list<_Up>, _Args&&...)): Likewise.
(__any_constructible): Likewise.
(__any_constructible_t): Use __any_constructible.
(operator=(_ValueType&&)): SFINAE in the return type.
(emplace(_Args&&...)): Likewise.
(emplace(initializer_list<_Up>, _Args&&...)): Likewise.
* include/std/optional (_Has_addressof_mem): Remove.
(_Has_addressof_free): Likewise.
(_Has_addressof): Likewise.
(__constexpr_addressof(_Tp&)): Likewise.
(operator->): Use std::__addressof.
* include/std/tuple (operator=(const tuple<_UElements...>&)):
SFINAE in return type.
(operator=(tuple<_UElements...>&&)): Likewise.
* testsuite/20_util/any/misc/any_cast_neg.cc: Adjust.
-------------- next part --------------
diff --git a/libstdc++-v3/include/std/any b/libstdc++-v3/include/std/any
index 45a2145..719e683 100644
--- a/libstdc++-v3/include/std/any
+++ b/libstdc++-v3/include/std/any
@@ -108,6 +108,27 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp, typename _Decayed = decay_t<_Tp>>
using _Decay = enable_if_t<!is_same<_Decayed, any>::value, _Decayed>;
+ /// Emplace with an object created from @p __args as the contained object.
+ template <typename _Tp, typename... _Args,
+ typename _Mgr = _Manager<_Tp>>
+ void __do_emplace(_Args&&... __args)
+ {
+ reset();
+ _M_manager = &_Mgr::_S_manage;
+ _Mgr::_S_create(_M_storage, std::forward<_Args>(__args)...);
+ }
+
+ /// Emplace with an object created from @p __il and @p __args as
+ /// the contained object.
+ template <typename _Tp, typename _Up, typename... _Args,
+ typename _Mgr = _Manager<_Tp>>
+ void __do_emplace(initializer_list<_Up> __il, _Args&&... __args)
+ {
+ reset();
+ _M_manager = &_Mgr::_S_manage;
+ _Mgr::_S_create(_M_storage, __il, std::forward<_Args>(__args)...);
+ }
+
public:
// construct/destruct
@@ -144,11 +165,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
}
+ template <typename _Res, typename _Tp, typename... _Args>
+ using __any_constructible =
+ enable_if<__and_<is_copy_constructible<_Tp>,
+ is_constructible<_Tp, _Args...>>::value,
+ _Res>;
+
template <typename _Tp, typename... _Args>
using __any_constructible_t =
- enable_if_t<__and_<is_copy_constructible<_Tp>,
- is_constructible<_Tp, _Args...>>::value,
- bool>;
+ typename __any_constructible<bool, _Tp, _Args...>::type;
/// Construct with a copy of @p __value as the contained object.
template <typename _ValueType, typename _Tp = _Decay<_ValueType>,
@@ -233,9 +258,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
/// Store a copy of @p __rhs as the contained object.
- template<typename _ValueType,
- typename _Tp = _Decay<_ValueType>>
- enable_if_t<is_copy_constructible<_Tp>::value, any&>
+ template<typename _ValueType>
+ enable_if_t<is_copy_constructible<_Decay<_ValueType>>::value, any&>
operator=(_ValueType&& __rhs)
{
*this = any(std::forward<_ValueType>(__rhs));
@@ -243,29 +267,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
/// Emplace with an object created from @p __args as the contained object.
- template <typename _ValueType, typename... _Args,
- typename _Tp = _Decay<_ValueType>,
- typename _Mgr = _Manager<_Tp>,
- __any_constructible_t<_Tp, _Args&&...> = false>
- void emplace(_Args&&... __args)
+ template <typename _ValueType, typename... _Args>
+ typename __any_constructible<void,
+ _Decay<_ValueType>, _Args&&...>::type
+ emplace(_Args&&... __args)
{
- reset();
- _M_manager = &_Mgr::_S_manage;
- _Mgr::_S_create(_M_storage, std::forward<_Args>(__args)...);
+ __do_emplace<_Decay<_ValueType>>
+ (std::forward<_Args>(__args)...);
}
/// Emplace with an object created from @p __il and @p __args as
/// the contained object.
- template <typename _ValueType, typename _Up, typename... _Args,
- typename _Tp = _Decay<_ValueType>,
- typename _Mgr = _Manager<_Tp>,
- __any_constructible_t<_Tp, initializer_list<_Up>,
- _Args&&...> = false>
- void emplace(initializer_list<_Up> __il, _Args&&... __args)
+ template <typename _ValueType, typename _Up, typename... _Args>
+ typename __any_constructible<void,
+ _Decay<_ValueType>,
+ initializer_list<_Up>,
+ _Args&&...>::type
+ emplace(initializer_list<_Up> __il, _Args&&... __args)
{
- reset();
- _M_manager = &_Mgr::_S_manage;
- _Mgr::_S_create(_M_storage, __il, std::forward<_Args>(__args)...);
+ __do_emplace<_Decay<_ValueType>, _Up>
+ (__il, std::forward<_Args>(__args)...);
}
// modifiers
diff --git a/libstdc++-v3/include/std/optional b/libstdc++-v3/include/std/optional
index f272876..35b6932 100644
--- a/libstdc++-v3/include/std/optional
+++ b/libstdc++-v3/include/std/optional
@@ -96,53 +96,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__throw_bad_optional_access(const char* __s)
{ _GLIBCXX_THROW_OR_ABORT(bad_optional_access(__s)); }
- template<typename _Tp, typename = void>
- struct _Has_addressof_mem : std::false_type { };
-
- template<typename _Tp>
- struct _Has_addressof_mem<_Tp,
- __void_t<decltype( std::declval<const _Tp&>().operator&() )>
- >
- : std::true_type { };
-
- template<typename _Tp, typename = void>
- struct _Has_addressof_free : std::false_type { };
-
- template<typename _Tp>
- struct _Has_addressof_free<_Tp,
- __void_t<decltype( operator&(std::declval<const _Tp&>()) )>
- >
- : 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 (e.g.
- * declval<const _Tp&>().operator&()).
- */
- template<typename _Tp>
- struct _Has_addressof
- : std::__or_<_Has_addressof_mem<_Tp>, _Has_addressof_free<_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, enable_if_t<!_Has_addressof<_Tp>::value, int>...>
- constexpr _Tp* __constexpr_addressof(_Tp& __t)
- { return &__t; }
-
- /**
- * @brief Fallback overload that defers to __addressof.
- */
- template<typename _Tp, enable_if_t<_Has_addressof<_Tp>::value, int>...>
- 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.
@@ -681,7 +634,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Observers.
constexpr const _Tp*
operator->() const
- { return __constexpr_addressof(this->_M_get()); }
+ { return std::__addressof(this->_M_get()); }
_Tp*
operator->()
diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple
index c06a040..63cacd4 100644
--- a/libstdc++-v3/include/std/tuple
+++ b/libstdc++-v3/include/std/tuple
@@ -846,20 +846,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return *this;
}
- template<typename... _UElements, typename = typename
+ template<typename... _UElements>
+ typename
enable_if<sizeof...(_UElements)
- == sizeof...(_Elements)>::type>
- tuple&
+ == sizeof...(_Elements), tuple&>::type
operator=(const tuple<_UElements...>& __in)
{
static_cast<_Inherited&>(*this) = __in;
return *this;
}
- template<typename... _UElements, typename = typename
+ template<typename... _UElements>
+ typename
enable_if<sizeof...(_UElements)
- == sizeof...(_Elements)>::type>
- tuple&
+ == sizeof...(_Elements), tuple&>::type
operator=(tuple<_UElements...>&& __in)
{
static_cast<_Inherited&>(*this) = std::move(__in);
diff --git a/libstdc++-v3/testsuite/20_util/any/misc/any_cast_neg.cc b/libstdc++-v3/testsuite/20_util/any/misc/any_cast_neg.cc
index 8b30666..4de400d 100644
--- a/libstdc++-v3/testsuite/20_util/any/misc/any_cast_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/any/misc/any_cast_neg.cc
@@ -26,5 +26,5 @@ void test01()
using std::any_cast;
const any y(1);
- any_cast<int&>(y); // { dg-error "qualifiers" "" { target { *-*-* } } 432 }
+ any_cast<int&>(y); // { dg-error "qualifiers" "" { target { *-*-* } } 453 }
}
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