[libc++] Declare std::tuple_element as struct instead of class
Similarly to https://reviews.llvm.org/rL350972, this revision changes
std::tuple_element from class to struct.
Fixes PR41331.
Thanks to Jan Wilken Dörrie for the patch.
Differential Revision: https://reviews.llvm.org/D60069
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@357411 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__tuple b/include/__tuple
index 89134b5..0381031 100644
--- a/include/__tuple
+++ b/include/__tuple
@@ -53,26 +53,23 @@
template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size<const volatile _Tp> : public tuple_size<_Tp> {};
#endif
-template <size_t _Ip, class _Tp> class _LIBCPP_TEMPLATE_VIS tuple_element;
+template <size_t _Ip, class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_element;
template <size_t _Ip, class _Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const _Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const _Tp>
{
-public:
typedef typename add_const<typename tuple_element<_Ip, _Tp>::type>::type type;
};
template <size_t _Ip, class _Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, volatile _Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, volatile _Tp>
{
-public:
typedef typename add_volatile<typename tuple_element<_Ip, _Tp>::type>::type type;
};
template <size_t _Ip, class _Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const volatile _Tp>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const volatile _Tp>
{
-public:
typedef typename add_cv<typename tuple_element<_Ip, _Tp>::type>::type type;
};
@@ -281,9 +278,8 @@
#endif
template <size_t _Ip, class ..._Types>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, __tuple_types<_Types...>>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, __tuple_types<_Types...>>
{
-public:
static_assert(_Ip < sizeof...(_Types), "tuple_element index out of range");
typedef __type_pack_element<_Ip, _Types...> type;
};
@@ -456,9 +452,8 @@
template <size_t _Ip, class ..._Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, tuple<_Tp...> >
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, tuple<_Tp...> >
{
-public:
typedef typename tuple_element<_Ip, __tuple_types<_Tp...> >::type type;
};
diff --git a/include/array b/include/array
index 418a2a9..88e9d57 100644
--- a/include/array
+++ b/include/array
@@ -91,7 +91,7 @@
void swap(array<T,N>& x, array<T,N>& y) noexcept(noexcept(x.swap(y))); // C++17
template <class T> struct tuple_size;
-template <size_t I, class T> class tuple_element;
+template <size_t I, class T> struct tuple_element;
template <class T, size_t N> struct tuple_size<array<T, N>>;
template <size_t I, class T, size_t N> struct tuple_element<I, array<T, N>>;
template <size_t I, class T, size_t N> T& get(array<T, N>&) noexcept; // constexpr in C++14
@@ -433,10 +433,9 @@
: public integral_constant<size_t, _Size> {};
template <size_t _Ip, class _Tp, size_t _Size>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
{
static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
-public:
typedef _Tp type;
};
diff --git a/include/span b/include/span
index 6b89d60..0694f51 100644
--- a/include/span
+++ b/include/span
@@ -531,11 +531,10 @@
template <size_t _Ip, class _Tp, size_t _Size>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, span<_Tp, _Size>>
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, span<_Tp, _Size>>
{
static_assert( dynamic_extent != _Size, "std::tuple_element<> not supported for std::span<T, dynamic_extent>");
static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::span)");
-public:
typedef _Tp type;
};
diff --git a/include/tuple b/include/tuple
index f7e7ee1..335e59e 100644
--- a/include/tuple
+++ b/include/tuple
@@ -87,8 +87,8 @@
template <class... T> struct tuple_size<tuple<T...>>;
template <class T>
inline constexpr size_t tuple_size_v = tuple_size<T>::value; // C++17
-template <size_t I, class T> class tuple_element; // undefined
-template <size_t I, class... T> class tuple_element<I, tuple<T...>>;
+template <size_t I, class T> struct tuple_element; // undefined
+template <size_t I, class... T> struct tuple_element<I, tuple<T...>>;
template <size_t I, class T>
using tuple_element_t = typename tuple_element <I, T>::type; // C++14
diff --git a/include/utility b/include/utility
index 770d160..3eea6f3 100644
--- a/include/utility
+++ b/include/utility
@@ -103,7 +103,7 @@
inline constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
template <class T> struct tuple_size;
-template <size_t I, class T> class tuple_element;
+template <size_t I, class T> struct tuple_element;
template <class T1, class T2> struct tuple_size<pair<T1, T2> >;
template <class T1, class T2> struct tuple_element<0, pair<T1, T2> >;
@@ -687,22 +687,20 @@
: public integral_constant<size_t, 2> {};
template <size_t _Ip, class _T1, class _T2>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, pair<_T1, _T2> >
+struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, pair<_T1, _T2> >
{
static_assert(_Ip < 2, "Index out of bounds in std::tuple_element<std::pair<T1, T2>>");
};
template <class _T1, class _T2>
-class _LIBCPP_TEMPLATE_VIS tuple_element<0, pair<_T1, _T2> >
+struct _LIBCPP_TEMPLATE_VIS tuple_element<0, pair<_T1, _T2> >
{
-public:
typedef _T1 type;
};
template <class _T1, class _T2>
-class _LIBCPP_TEMPLATE_VIS tuple_element<1, pair<_T1, _T2> >
+struct _LIBCPP_TEMPLATE_VIS tuple_element<1, pair<_T1, _T2> >
{
-public:
typedef _T2 type;
};
diff --git a/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp b/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp
index a97e60c..c3619f7 100644
--- a/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp
+++ b/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp
@@ -11,9 +11,8 @@
// template <class... Types> class tuple;
// template <size_t I, class... Types>
-// class tuple_element<I, tuple<Types...> >
+// struct tuple_element<I, tuple<Types...> >
// {
-// public:
// typedef Ti type;
// };
//
diff --git a/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_element.fail.cpp b/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_element.fail.cpp
index 24b735b..7fee551 100644
--- a/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_element.fail.cpp
+++ b/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_element.fail.cpp
@@ -11,9 +11,8 @@
// template <class... Types> class tuple;
// template <size_t I, class... Types>
-// class tuple_element<I, tuple<Types...> >
+// struct tuple_element<I, tuple<Types...> >
// {
-// public:
// typedef Ti type;
// };
diff --git a/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_element.pass.cpp b/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_element.pass.cpp
index 5ad2b08..60bbe39 100644
--- a/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_element.pass.cpp
+++ b/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_element.pass.cpp
@@ -11,9 +11,8 @@
// template <class... Types> class tuple;
// template <size_t I, class... Types>
-// class tuple_element<I, tuple<Types...> >
+// struct tuple_element<I, tuple<Types...> >
// {
-// public:
// typedef Ti type;
// };
diff --git a/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_size_structured_bindings.pass.cpp b/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_size_structured_bindings.pass.cpp
index 00f7ff2..28186a7 100644
--- a/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_size_structured_bindings.pass.cpp
+++ b/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple_size_structured_bindings.pass.cpp
@@ -116,8 +116,7 @@
int get(Test const&) { static_assert(N == 0, ""); return -1; }
template <>
-class std::tuple_element<0, Test> {
-public:
+struct std::tuple_element<0, Test> {
typedef int type;
};
