Revert r372777: [libc++] Implement LWG 2510 and its follow-ups
This also reverts:
- r372778: [libc++] Implement LWG 3158
- r372782: [libc++] Try fixing tests that fail on GCC 5 and older
- r372787: Purge mentions of GCC 4 from the test suite
Reason: the change breaks compilation of LLVM with libc++, for details see
http://lists.llvm.org/pipermail/libcxx-dev/2019-September/000599.html
llvm-svn: 372832
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: a3d337a9a7d00d82bb190c5e551181d3998f6b98
diff --git a/include/__functional_base b/include/__functional_base
index ca761c4..9587d7a 100644
--- a/include/__functional_base
+++ b/include/__functional_base
@@ -558,7 +558,7 @@
// allocator_arg_t
-struct _LIBCPP_TEMPLATE_VIS allocator_arg_t { explicit allocator_arg_t() = default; };
+struct _LIBCPP_TEMPLATE_VIS allocator_arg_t { };
#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
extern _LIBCPP_EXPORTED_FROM_ABI const allocator_arg_t allocator_arg;
diff --git a/include/__mutex_base b/include/__mutex_base
index ed75c82..a4ac361 100644
--- a/include/__mutex_base
+++ b/include/__mutex_base
@@ -66,9 +66,9 @@
static_assert(is_nothrow_default_constructible<mutex>::value,
"the default constructor for std::mutex must be nothrow");
-struct _LIBCPP_TYPE_VIS defer_lock_t { explicit defer_lock_t() = default; };
-struct _LIBCPP_TYPE_VIS try_to_lock_t { explicit try_to_lock_t() = default; };
-struct _LIBCPP_TYPE_VIS adopt_lock_t { explicit adopt_lock_t() = default; };
+struct _LIBCPP_TYPE_VIS defer_lock_t {};
+struct _LIBCPP_TYPE_VIS try_to_lock_t {};
+struct _LIBCPP_TYPE_VIS adopt_lock_t {};
#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
diff --git a/include/mutex b/include/mutex
index 8fc3c61..dca6220 100644
--- a/include/mutex
+++ b/include/mutex
@@ -86,9 +86,9 @@
void unlock();
};
-struct defer_lock_t { explicit defer_lock_t() = default; };
-struct try_to_lock_t { explicit try_to_lock_t() = default; };
-struct adopt_lock_t { explicit adopt_lock_t() = default; };
+struct defer_lock_t {};
+struct try_to_lock_t {};
+struct adopt_lock_t {};
inline constexpr defer_lock_t defer_lock{};
inline constexpr try_to_lock_t try_to_lock{};
diff --git a/include/new b/include/new
index 40d351e..85e4c4b 100644
--- a/include/new
+++ b/include/new
@@ -39,7 +39,7 @@
};
inline constexpr destroying_delete_t destroying_delete{}; // C++20
-struct nothrow_t { explicit nothrow_t() = default; };
+struct nothrow_t {};
extern const nothrow_t nothrow;
typedef void (*new_handler)();
new_handler set_new_handler(new_handler new_p) noexcept;
@@ -126,7 +126,7 @@
{
#if !defined(_LIBCPP_ABI_VCRUNTIME)
-struct _LIBCPP_TYPE_VIS nothrow_t { explicit nothrow_t() = default; };
+struct _LIBCPP_TYPE_VIS nothrow_t {};
extern _LIBCPP_FUNC_VIS const nothrow_t nothrow;
class _LIBCPP_EXCEPTION_ABI bad_alloc
diff --git a/include/tuple b/include/tuple
index c4cd3bc..32bc869 100644
--- a/include/tuple
+++ b/include/tuple
@@ -19,7 +19,7 @@
template <class... T>
class tuple {
public:
- explicit(see-below) constexpr tuple();
+ constexpr tuple();
explicit(see-below) tuple(const T&...); // constexpr in C++14
template <class... U>
explicit(see-below) tuple(U&&...); // constexpr in C++14
@@ -500,22 +500,9 @@
struct _CheckArgsConstructor<true, _Dummy>
{
template <class ..._Args>
- struct __enable_implicit_default
- // In C++03, there's no way to implement the resolution of LWG2510.
-#ifdef _LIBCPP_CXX03_LANG
- : true_type
-#else
- : __all<__is_implicitly_default_constructible<_Args>::value...>
-#endif
- { };
-
- template <class ..._Args>
- struct __enable_explicit_default
- : integral_constant<bool,
- __all<is_default_constructible<_Args>::value...>::value &&
- !__enable_implicit_default<_Args...>::value
- >
- { };
+ static constexpr bool __enable_default() {
+ return __all<is_default_constructible<_Args>::value...>::value;
+ }
template <class ..._Args>
static constexpr bool __enable_explicit() {
@@ -654,29 +641,22 @@
const typename tuple_element<_Jp, tuple<_Up...> >::type&& get(const tuple<_Up...>&&) _NOEXCEPT;
public:
- template <bool _Dummy = true, _EnableIf<
- _CheckArgsConstructor<_Dummy>::template __enable_implicit_default<_Tp...>::value
- , void*> = nullptr>
- _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
- tuple()
- _NOEXCEPT_(__all<is_nothrow_default_constructible<_Tp>::value...>::value) {}
-
- template <bool _Dummy = true, _EnableIf<
- _CheckArgsConstructor<_Dummy>::template __enable_explicit_default<_Tp...>::value
- , void*> = nullptr>
- explicit _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
- tuple()
+ template <bool _Dummy = true, class = typename enable_if<
+ _CheckArgsConstructor<_Dummy>::template __enable_default<_Tp...>()
+ >::type>
+ _LIBCPP_INLINE_VISIBILITY
+ _LIBCPP_CONSTEXPR tuple()
_NOEXCEPT_(__all<is_nothrow_default_constructible<_Tp>::value...>::value) {}
tuple(tuple const&) = default;
tuple(tuple&&) = default;
- template <class _AllocArgT, class _Alloc, bool _Dummy = true, _EnableIf<
+ template <class _AllocArgT, class _Alloc, bool _Dummy = true, class = _EnableIf<
_And<
_IsSame<allocator_arg_t, _AllocArgT>,
- typename _CheckArgsConstructor<_Dummy>::template __enable_implicit_default<_Tp...>
+ __dependent_type<is_default_constructible<_Tp>, _Dummy>...
>::value
- , void*> = nullptr
+ >
>
_LIBCPP_INLINE_VISIBILITY
tuple(_AllocArgT, _Alloc const& __a)
@@ -685,20 +665,6 @@
typename __make_tuple_indices<sizeof...(_Tp), 0>::type(),
__tuple_types<_Tp...>()) {}
- template <class _AllocArgT, class _Alloc, bool _Dummy = true, _EnableIf<
- _And<
- _IsSame<allocator_arg_t, _AllocArgT>,
- typename _CheckArgsConstructor<_Dummy>::template __enable_explicit_default<_Tp...>
- >::value
- , void*> = nullptr
- >
- explicit _LIBCPP_INLINE_VISIBILITY
- tuple(_AllocArgT, _Alloc const& __a)
- : __base_(allocator_arg_t(), __a,
- __tuple_indices<>(), __tuple_types<>(),
- typename __make_tuple_indices<sizeof...(_Tp), 0>::type(),
- __tuple_types<_Tp...>()) {}
-
template <bool _Dummy = true,
typename enable_if
<
diff --git a/include/type_traits b/include/type_traits
index cb3ed97..ee17824 100644
--- a/include/type_traits
+++ b/include/type_traits
@@ -2807,21 +2807,6 @@
= is_default_constructible<_Tp>::value;
#endif
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp>
-void __test_implicit_default_constructible(_Tp);
-
-template <class _Tp, class = void>
-struct __is_implicitly_default_constructible
- : false_type
-{ };
-
-template <class _Tp>
-struct __is_implicitly_default_constructible<_Tp, decltype(__test_implicit_default_constructible<_Tp const&>({}))>
- : is_default_constructible<_Tp>
-{ };
-#endif // !C++03
-
// is_copy_constructible
template <class _Tp>
diff --git a/include/utility b/include/utility
index c90d049..64599c8 100644
--- a/include/utility
+++ b/include/utility
@@ -69,7 +69,7 @@
pair(const pair&) = default;
pair(pair&&) = default;
- explicit(see-below) constexpr pair();
+ constexpr pair();
explicit(see-below) pair(const T1& x, const T2& y); // constexpr in C++14
template <class U, class V> explicit(see-below) pair(U&& x, V&& y); // constexpr in C++14
template <class U, class V> explicit(see-below) pair(const pair<U, V>& p); // constexpr in C++14
@@ -99,7 +99,7 @@
void
swap(pair<T1, T2>& x, pair<T1, T2>& y) noexcept(noexcept(x.swap(y)));
-struct piecewise_construct_t { explicit piecewise_construct_t() = default; };
+struct piecewise_construct_t { };
inline constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
template <class T> struct tuple_size;
@@ -276,7 +276,7 @@
template <class _Tp> void as_const(const _Tp&&) = delete;
#endif
-struct _LIBCPP_TEMPLATE_VIS piecewise_construct_t { explicit piecewise_construct_t() = default; };
+struct _LIBCPP_TEMPLATE_VIS piecewise_construct_t { };
#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
extern _LIBCPP_EXPORTED_FROM_ABI const piecewise_construct_t piecewise_construct;// = piecewise_construct_t();
#else
@@ -335,21 +335,9 @@
struct _CheckArgs {
template <class _U1, class _U2>
- static constexpr bool __enable_explicit_default() {
+ static constexpr bool __enable_default() {
return is_default_constructible<_U1>::value
- && is_default_constructible<_U2>::value
- && !__enable_implicit_default<_U1, _U2>();
- }
-
- template <class _U1, class _U2>
- static constexpr bool __enable_implicit_default() {
- // In C++03, there's no way to implement the resolution of LWG2510.
-#ifdef _LIBCPP_CXX03_LANG
- return true;
-#else
- return __is_implicitly_default_constructible<_U1>::value
- && __is_implicitly_default_constructible<_U2>::value;
-#endif
+ && is_default_constructible<_U2>::value;
}
template <class _U1, class _U2>
@@ -400,15 +388,7 @@
>::type;
template<bool _Dummy = true, _EnableB<
- _CheckArgsDep<_Dummy>::template __enable_explicit_default<_T1, _T2>()
- > = false>
- explicit _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
- pair() _NOEXCEPT_(is_nothrow_default_constructible<first_type>::value &&
- is_nothrow_default_constructible<second_type>::value)
- : first(), second() {}
-
- template<bool _Dummy = true, _EnableB<
- _CheckArgsDep<_Dummy>::template __enable_implicit_default<_T1, _T2>()
+ _CheckArgsDep<_Dummy>::template __enable_default<_T1, _T2>()
> = false>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
pair() _NOEXCEPT_(is_nothrow_default_constructible<first_type>::value &&