Work around bad MSVC bug regarding friend functions

Author: miscco

libcudacxx/include/cuda/std/detail/libcxx/include/tuple

@@ -656,20 +656,39 @@ class _LIBCUDACXX_TEMPLATE_VIS tuple
   struct _PackExpandsToThisTuple<_Arg> : is_same<__remove_cvref_t<_Arg>, tuple>
   {};
 
-  template <size_t _Jp, class... _Up>
-  friend _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 _LIBCUDACXX_INLINE_VISIBILITY __tuple_element_t<_Jp, tuple<_Up...>>& get(
-      tuple<_Up...>&) noexcept;
-  template <size_t _Jp, class... _Up>
-  friend _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 _LIBCUDACXX_INLINE_VISIBILITY const __tuple_element_t<_Jp, tuple<_Up...>>&
-  get(const tuple<_Up...>&) noexcept;
-  template <size_t _Jp, class... _Up>
-  friend _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 _LIBCUDACXX_INLINE_VISIBILITY __tuple_element_t<_Jp, tuple<_Up...>>&& get(
-      tuple<_Up...>&&) noexcept;
-  template <size_t _Jp, class... _Up>
-  friend _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 _LIBCUDACXX_INLINE_VISIBILITY const __tuple_element_t<_Jp, tuple<_Up...>>&&
-  get(const tuple<_Up...>&&) noexcept;
-
 public:
+  template <size_t _Ip>
+  _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 __tuple_element_t<_Ip, tuple>&
+  __get_impl() & noexcept
+  {
+    typedef _LIBCUDACXX_NODEBUG_TYPE __tuple_element_t<_Ip, tuple> type;
+    return static_cast<__tuple_leaf<_Ip, type>&>(__base_).get();
+  }
+
+  template <size_t _Ip>
+  _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 const __tuple_element_t<_Ip, tuple>&
+  __get_impl() const& noexcept
+  {
+    typedef _LIBCUDACXX_NODEBUG_TYPE __tuple_element_t<_Ip, tuple> type;
+    return static_cast<const __tuple_leaf<_Ip, type>&>(__base_).get();
+  }
+
+  template <size_t _Ip>
+  _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 __tuple_element_t<_Ip, tuple>&&
+  __get_impl() && noexcept
+  {
+    typedef _LIBCUDACXX_NODEBUG_TYPE __tuple_element_t<_Ip, tuple> type;
+    return static_cast<type&&>(static_cast<__tuple_leaf<_Ip, type>&&>(__base_).get());
+  }
+
+  template <size_t _Ip>
+  _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 const __tuple_element_t<_Ip, tuple>&&
+  __get_impl() const&& noexcept
+  {
+    typedef _LIBCUDACXX_NODEBUG_TYPE __tuple_element_t<_Ip, tuple> type;
+    return static_cast<const type&&>(static_cast<const __tuple_leaf<_Ip, type>&&>(__base_).get());
+  }
+
   template < class _Constraints                                          = __tuple_constraints<_Tp...>,
       __enable_if_t<_Constraints::__implicit_default_constructible, int> = 0>
   _LIBCUDACXX_INLINE_VISIBILITY constexpr tuple() noexcept(_Constraints::__nothrow_default_constructible)
@@ -919,32 +938,28 @@ template <size_t _Ip, class... _Tp>
 inline _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 __tuple_element_t<_Ip, tuple<_Tp...>>&
 get(tuple<_Tp...>& __t) noexcept
 {
-  typedef _LIBCUDACXX_NODEBUG_TYPE __tuple_element_t<_Ip, tuple<_Tp...>> type;
-  return static_cast<__tuple_leaf<_Ip, type>&>(__t.__base_).get();
+  return __t.template __get_impl<_Ip>();
 }
 
 template <size_t _Ip, class... _Tp>
 inline _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 const __tuple_element_t<_Ip, tuple<_Tp...>>&
 get(const tuple<_Tp...>& __t) noexcept
 {
-  typedef _LIBCUDACXX_NODEBUG_TYPE __tuple_element_t<_Ip, tuple<_Tp...>> type;
-  return static_cast<const __tuple_leaf<_Ip, type>&>(__t.__base_).get();
+  return __t.template __get_impl<_Ip>();
 }
 
 template <size_t _Ip, class... _Tp>
 inline _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 __tuple_element_t<_Ip, tuple<_Tp...>>&&
 get(tuple<_Tp...>&& __t) noexcept
 {
-  typedef _LIBCUDACXX_NODEBUG_TYPE __tuple_element_t<_Ip, tuple<_Tp...>> type;
-  return static_cast<type&&>(static_cast<__tuple_leaf<_Ip, type>&&>(__t.__base_).get());
+  return _CUDA_VSTD::move(__t).template __get_impl<_Ip>();
 }
 
 template <size_t _Ip, class... _Tp>
 inline _LIBCUDACXX_INLINE_VISIBILITY _LIBCUDACXX_CONSTEXPR_AFTER_CXX11 const __tuple_element_t<_Ip, tuple<_Tp...>>&&
 get(const tuple<_Tp...>&& __t) noexcept
 {
-  typedef _LIBCUDACXX_NODEBUG_TYPE __tuple_element_t<_Ip, tuple<_Tp...>> type;
-  return static_cast<const type&&>(static_cast<const __tuple_leaf<_Ip, type>&&>(__t.__base_).get());
+  return static_cast<const tuple<_Tp...>&&>(__t).template __get_impl<_Ip>();
 }
 
 #if _LIBCUDACXX_STD_VER > 11