Implement the std::pair parts of "Improving pair and tuple". Completes N4387.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@276605 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/utility b/include/utility
index 456a5f7..fbb06f3 100644
--- a/include/utility
+++ b/include/utility
@@ -291,6 +291,7 @@
constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
#endif
+
template <class _T1, class _T2>
struct _LIBCPP_TYPE_VIS_ONLY pair
{
@@ -300,28 +301,6 @@
_T1 first;
_T2 second;
-#ifndef _LIBCPP_HAS_NO_DEFAULT_FUNCTION_TEMPLATE_ARGS
- template <bool _Dummy = true, class = typename enable_if<
- __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
- __dependent_type<is_default_constructible<_T2>, _Dummy>::value
- >::type>
-#endif
- _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR pair() : first(), second() {}
-
- _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
- pair(const _T1& __x, const _T2& __y)
- : first(__x), second(__y) {}
-
- template<class _U1, class _U2>
- _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
- pair(const pair<_U1, _U2>& __p
-#ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
- ,typename enable_if<is_convertible<const _U1&, _T1>::value &&
- is_convertible<const _U2&, _T2>::value>::type* = 0
-#endif
- )
- : first(__p.first), second(__p.second) {}
-
#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
_LIBCPP_INLINE_VISIBILITY
pair(const pair& __p)
@@ -348,23 +327,172 @@
// Use the implicitly declared copy constructor in C++03
#endif
-#if !defined(_LIBCPP_CXX03_LANG)
- typedef typename conditional<
- is_copy_assignable<_T1>::value
- && is_copy_assignable<_T2>::value,
- pair, __nat
- >::type _CopyAssignT;
- typedef typename conditional<
- is_move_assignable<_T1>::value
- && is_move_assignable<_T2>::value,
- pair, __nat
- >::type _MoveAssignT;
-#else
- typedef pair _CopyAssignT;
-#endif
+#ifdef _LIBCPP_CXX03_LANG
+ _LIBCPP_INLINE_VISIBILITY
+ pair() : first(), second() {}
_LIBCPP_INLINE_VISIBILITY
- pair& operator=(_CopyAssignT const& __p)
+ pair(_T1 const& __t1, _T2 const& __t2) : first(__t1), second(__t2) {}
+
+ template <class _U1, class _U2>
+ _LIBCPP_INLINE_VISIBILITY
+ pair(const pair<_U1, _U2>& __p) : first(__p.first), second(__p.second) {}
+
+ _LIBCPP_INLINE_VISIBILITY
+ pair& operator=(pair const& __p) {
+ first = __p.first;
+ second = __p.second;
+ return *this;
+ }
+#else
+ template <bool _Val>
+ using _EnableB = typename enable_if<_Val, bool>::type;
+
+ struct _CheckArgs {
+ template <class _U1, class _U2>
+ static constexpr bool __enable_default() {
+ return is_default_constructible<_U1>::value
+ && is_default_constructible<_U2>::value;
+ }
+
+ template <class _U1, class _U2>
+ static constexpr bool __enable_explicit() {
+ return is_constructible<first_type, _U1>::value
+ && is_constructible<second_type, _U2>::value
+ && (!is_convertible<_U1, first_type>::value
+ || !is_convertible<_U2, second_type>::value);
+ }
+
+ template <class _U1, class _U2>
+ static constexpr bool __enable_implicit() {
+ return is_constructible<first_type, _U1>::value
+ && is_constructible<second_type, _U2>::value
+ && is_convertible<_U1, first_type>::value
+ && is_convertible<_U2, second_type>::value;
+ }
+ };
+
+ template <bool _MaybeEnable>
+ using _CheckArgsDep = typename conditional<
+ _MaybeEnable, _CheckArgs, __check_tuple_constructor_fail>::type;
+
+ struct _CheckTupleLikeConstructor {
+ template <class _Tuple>
+ static constexpr bool __enable_implicit() {
+ return __tuple_convertible<_Tuple, pair>::value;
+ }
+
+ template <class _Tuple>
+ static constexpr bool __enable_explicit() {
+ return __tuple_constructible<_Tuple, pair>::value
+ && !__tuple_convertible<_Tuple, pair>::value;
+ }
+
+ template <class _Tuple>
+ static constexpr bool __enable_assign() {
+ return __tuple_assignable<_Tuple, pair>::value;
+ }
+ };
+
+ template <class _Tuple>
+ using _CheckTLC = typename conditional<
+ __tuple_like_with_size<_Tuple, 2>::value
+ && !is_same<typename decay<_Tuple>::type, pair>::value,
+ _CheckTupleLikeConstructor,
+ __check_tuple_constructor_fail
+ >::type;
+
+ template<bool _Dummy = true, _EnableB<
+ _CheckArgsDep<_Dummy>::template __enable_default<_T1, _T2>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+ pair() : first(), second() {}
+
+ template <bool _Dummy = true, _EnableB<
+ _CheckArgsDep<_Dummy>::template __enable_explicit<_T1 const&, _T2 const&>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ explicit pair(_T1 const& __t1, _T2 const& __t2)
+ : first(__t1), second(__t2) {}
+
+ template<bool _Dummy = true, _EnableB<
+ _CheckArgsDep<_Dummy>::template __enable_implicit<_T1 const&, _T2 const&>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ pair(_T1 const& __t1, _T2 const& __t2)
+ : first(__t1), second(__t2) {}
+
+ template<class _U1, class _U2, _EnableB<
+ _CheckArgs::template __enable_explicit<_U1, _U2>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ explicit pair(_U1&& __u1, _U2&& __u2)
+ : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
+
+ template<class _U1, class _U2, _EnableB<
+ _CheckArgs::template __enable_implicit<_U1, _U2>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ pair(_U1&& __u1, _U2&& __u2)
+ : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
+
+ template<class _U1, class _U2, _EnableB<
+ _CheckArgs::template __enable_explicit<_U1 const&, _U2 const&>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ explicit pair(pair<_U1, _U2> const& __p)
+ : first(__p.first), second(__p.second) {}
+
+ template<class _U1, class _U2, _EnableB<
+ _CheckArgs::template __enable_implicit<_U1 const&, _U2 const&>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ pair(pair<_U1, _U2> const& __p)
+ : first(__p.first), second(__p.second) {}
+
+ template<class _U1, class _U2, _EnableB<
+ _CheckArgs::template __enable_explicit<_U1, _U2>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ explicit pair(pair<_U1, _U2>&&__p)
+ : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
+
+ template<class _U1, class _U2, _EnableB<
+ _CheckArgs::template __enable_implicit<_U1, _U2>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ pair(pair<_U1, _U2>&& __p)
+ : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
+
+ template<class _Tuple, _EnableB<
+ _CheckTLC<_Tuple>::template __enable_explicit<_Tuple>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ explicit pair(_Tuple&& __p)
+ : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
+ second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
+
+ template<class _Tuple, _EnableB<
+ _CheckTLC<_Tuple>::template __enable_implicit<_Tuple>()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ pair(_Tuple&& __p)
+ : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
+ second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
+
+ template <class... _Args1, class... _Args2>
+ _LIBCPP_INLINE_VISIBILITY
+ pair(piecewise_construct_t __pc,
+ tuple<_Args1...> __first_args, tuple<_Args2...> __second_args)
+ : pair(__pc, __first_args, __second_args,
+ typename __make_tuple_indices<sizeof...(_Args1)>::type(),
+ typename __make_tuple_indices<sizeof...(_Args2) >::type()) {}
+
+ _LIBCPP_INLINE_VISIBILITY
+ pair& operator=(typename conditional<
+ is_copy_assignable<first_type>::value &&
+ is_copy_assignable<second_type>::value,
+ pair, __nat>::type const& __p)
_NOEXCEPT_(is_nothrow_copy_assignable<first_type>::value &&
is_nothrow_copy_assignable<second_type>::value)
{
@@ -373,9 +501,11 @@
return *this;
}
-#ifndef _LIBCPP_CXX03_LANG
_LIBCPP_INLINE_VISIBILITY
- pair& operator=(_MoveAssignT&& __p)
+ pair& operator=(typename conditional<
+ is_move_assignable<first_type>::value &&
+ is_move_assignable<second_type>::value,
+ pair, __nat>::type&& __p)
_NOEXCEPT_(is_nothrow_move_assignable<first_type>::value &&
is_nothrow_move_assignable<second_type>::value)
{
@@ -383,68 +513,18 @@
second = _VSTD::forward<second_type>(__p.second);
return *this;
}
+
+ template <class _Tuple, _EnableB<
+ _CheckTLC<_Tuple>::template __enable_assign()
+ > = false>
+ _LIBCPP_INLINE_VISIBILITY
+ pair& operator=(_Tuple&& __p) {
+ first = _VSTD::get<0>(_VSTD::forward<_Tuple>(__p));
+ second = _VSTD::get<1>(_VSTD::forward<_Tuple>(__p));
+ return *this;
+ }
#endif
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
- template <class _U1, class _U2,
- class = typename enable_if<is_convertible<_U1, first_type>::value &&
- is_convertible<_U2, second_type>::value>::type>
- _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
- pair(_U1&& __u1, _U2&& __u2)
- : first(_VSTD::forward<_U1>(__u1)),
- second(_VSTD::forward<_U2>(__u2))
- {}
-
- template<class _U1, class _U2>
- _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
- pair(pair<_U1, _U2>&& __p,
- typename enable_if<is_convertible<_U1, _T1>::value &&
- is_convertible<_U2, _T2>::value>::type* = 0)
- : first(_VSTD::forward<_U1>(__p.first)),
- second(_VSTD::forward<_U2>(__p.second)) {}
-
-
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
- template<class _Tuple,
- class = typename enable_if<__tuple_convertible<_Tuple, pair>::value>::type>
- _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
- pair(_Tuple&& __p)
- : first(_VSTD::forward<typename tuple_element<0,
- typename __make_tuple_types<_Tuple>::type>::type>(_VSTD::get<0>(__p))),
- second(_VSTD::forward<typename tuple_element<1,
- typename __make_tuple_types<_Tuple>::type>::type>(_VSTD::get<1>(__p)))
- {}
-
-
-
- template <class... _Args1, class... _Args2>
- _LIBCPP_INLINE_VISIBILITY
- pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
- tuple<_Args2...> __second_args)
- : pair(__pc, __first_args, __second_args,
- typename __make_tuple_indices<sizeof...(_Args1)>::type(),
- typename __make_tuple_indices<sizeof...(_Args2) >::type())
- {}
-
- template <class _Tuple,
- class = typename enable_if<!is_same<typename decay<_Tuple>::type, pair>::value && __tuple_assignable<_Tuple, pair>::value>::type>
- _LIBCPP_INLINE_VISIBILITY
- pair&
- operator=(_Tuple&& __p)
- {
- typedef typename __make_tuple_types<_Tuple>::type _TupleRef;
- typedef typename tuple_element<0, _TupleRef>::type _U0;
- typedef typename tuple_element<1, _TupleRef>::type _U1;
- first = _VSTD::forward<_U0>(_VSTD::get<0>(__p));
- second = _VSTD::forward<_U1>(_VSTD::get<1>(__p));
- return *this;
- }
-
-#endif // _LIBCPP_HAS_NO_VARIADICS
-
-#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
_LIBCPP_INLINE_VISIBILITY
void
swap(pair& __p) _NOEXCEPT_(__is_nothrow_swappable<first_type>::value &&
@@ -456,13 +536,13 @@
}
private:
-#ifndef _LIBCPP_HAS_NO_VARIADICS
+#ifndef _LIBCPP_CXX03_LANG
template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
_LIBCPP_INLINE_VISIBILITY
pair(piecewise_construct_t,
tuple<_Args1...>& __first_args, tuple<_Args2...>& __second_args,
__tuple_indices<_I1...>, __tuple_indices<_I2...>);
-#endif // _LIBCPP_HAS_NO_VARIADICS
+#endif
};
template <class _T1, class _T2>