[libcxx-commits] [PATCH] D148466: [libc++][NFC] Remove some dead code in common_type

[Nikolas Klauser via Phabricator via libcxx-commits]

philnik created this revision.
Herald added a project: All.
philnik requested review of this revision.
Herald added a project: libc++.
Herald added a subscriber: libcxx-commits.
Herald added a reviewer: libc++.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D148466

Files:
  libcxx/include/__type_traits/common_type.h


Index: libcxx/include/__type_traits/common_type.h
===================================================================
--- libcxx/include/__type_traits/common_type.h
+++ libcxx/include/__type_traits/common_type.h
@@ -57,25 +57,10 @@
 template <class, class = void>
 struct __common_type_impl {};
 
-// Clang provides variadic templates in C++03 as an extension.
-#if !defined(_LIBCPP_CXX03_LANG) || defined(__clang__)
-# define _LIBCPP_OPTIONAL_PACK(...) , __VA_ARGS__
 template <class... _Tp>
 struct __common_types;
 template <class... _Tp>
 struct _LIBCPP_TEMPLATE_VIS common_type;
-#else
-# define _LIBCPP_OPTIONAL_PACK(...)
-struct __no_arg;
-template <class _Tp, class _Up, class = __no_arg>
-struct __common_types;
-template <class _Tp = __no_arg, class _Up = __no_arg, class _Vp = __no_arg,
-          class _Unused = __no_arg>
-struct common_type {
-  static_assert(sizeof(_Unused) == 0,
-                "common_type accepts at most 3 arguments in C++03");
-};
-#endif // _LIBCPP_CXX03_LANG
 
 template <class _Tp, class _Up>
 struct __common_type_impl<
@@ -84,12 +69,12 @@
   typedef typename common_type<_Tp, _Up>::type type;
 };
 
-template <class _Tp, class _Up, class _Vp _LIBCPP_OPTIONAL_PACK(class... _Rest)>
+template <class _Tp, class _Up, class _Vp, class... _Rest>
 struct __common_type_impl<
-    __common_types<_Tp, _Up, _Vp _LIBCPP_OPTIONAL_PACK(_Rest...)>,
+    __common_types<_Tp, _Up, _Vp, _Rest...>,
     __void_t<typename common_type<_Tp, _Up>::type> >
     : __common_type_impl<__common_types<typename common_type<_Tp, _Up>::type,
-                                        _Vp _LIBCPP_OPTIONAL_PACK(_Rest...)> > {
+                                        _Vp, _Rest...> > {
 };
 
 // bullet 1 - sizeof...(Tp) == 0
@@ -117,13 +102,11 @@
 
 // bullet 4 - sizeof...(Tp) > 2
 
-template <class _Tp, class _Up, class _Vp _LIBCPP_OPTIONAL_PACK(class... _Rest)>
+template <class _Tp, class _Up, class _Vp, class... _Rest>
 struct _LIBCPP_TEMPLATE_VIS
-    common_type<_Tp, _Up, _Vp _LIBCPP_OPTIONAL_PACK(_Rest...)>
+    common_type<_Tp, _Up, _Vp, _Rest...>
     : __common_type_impl<
-          __common_types<_Tp, _Up, _Vp _LIBCPP_OPTIONAL_PACK(_Rest...)> > {};
-
-#undef _LIBCPP_OPTIONAL_PACK
+          __common_types<_Tp, _Up, _Vp, _Rest...> > {};
 
 #if _LIBCPP_STD_VER >= 14
 template <class ..._Tp> using common_type_t = typename common_type<_Tp...>::type;


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