Bug 1625138 - Part 28: Replace mozilla::AddRvalueReference with std::add_rvalue_reference. r=froydnj

Differential Revision: https://phabricator.services.mozilla.com/D68546

--HG--
extra : moz-landing-system : lando

mfbt/TypeTraits.h

@@ -219,45 +219,6 @@ struct RemoveCV {
   typedef typename RemoveConst<typename RemoveVolatile<T>::Type>::Type Type;
 };
 
-/* 20.9.7.2 Reference modifications [meta.trans.ref] */
-
-namespace detail {
-
-enum Voidness { TIsVoid, TIsNotVoid };
-
-template <typename T, Voidness V = IsVoid<T>::value ? TIsVoid : TIsNotVoid>
-struct AddRvalueReferenceHelper;
-
-template <typename T>
-struct AddRvalueReferenceHelper<T, TIsVoid> {
-  typedef void Type;
-};
-
-template <typename T>
-struct AddRvalueReferenceHelper<T, TIsNotVoid> {
-  typedef T&& Type;
-};
-
-}  // namespace detail
-
-/**
- * AddRvalueReference adds an rvalue && reference to T if one isn't already
- * present. (Note: adding an rvalue reference to an lvalue & reference in
- * essence keeps the &, per C+11 reference collapsing rules. For example,
- * int& would remain int&.)
- *
- * The final computed type will only *not* be a reference if T is void.
- *
- * mozilla::AddRvalueReference<int>::Type is int&&;
- * mozilla::AddRvalueRference<volatile int&>::Type is volatile int&;
- * mozilla::AddRvalueRference<const int&&>::Type is const int&&;
- * mozilla::AddRvalueReference<void*>::Type is void*&&;
- * mozilla::AddRvalueReference<void>::Type is void;
- * mozilla::AddRvalueReference<struct S&>::Type is struct S&.
- */
-template <typename T>
-struct AddRvalueReference : detail::AddRvalueReferenceHelper<T> {};
-
 } /* namespace mozilla */
 
 #endif /* mozilla_TypeTraits_h */

mfbt/tests/TestTypeTraits.cpp

@@ -7,7 +7,6 @@
 #include "mozilla/Assertions.h"
 #include "mozilla/TypeTraits.h"
 
-using mozilla::AddRvalueReference;
 using mozilla::IsDestructible;
 using mozilla::IsSame;
 
@@ -28,20 +27,6 @@ static_assert(!IsDestructible<PrivateDestructible>::value,
 static_assert(IsDestructible<TrivialDestructible>::value,
               "trivial destructible class is destructible");
 
-static_assert(IsSame<AddRvalueReference<int>::Type, int&&>::value,
-              "not adding && to int correctly");
-static_assert(
-    IsSame<AddRvalueReference<volatile int&>::Type, volatile int&>::value,
-    "not adding && to volatile int& correctly");
-static_assert(IsSame<AddRvalueReference<const int&&>::Type, const int&&>::value,
-              "not adding && to volatile int& correctly");
-static_assert(IsSame<AddRvalueReference<void*>::Type, void*&&>::value,
-              "not adding && to void* correctly");
-static_assert(IsSame<AddRvalueReference<void>::Type, void>::value,
-              "void shouldn't be transformed by AddRvalueReference");
-static_assert(IsSame<AddRvalueReference<struct S1&>::Type, struct S1&>::value,
-              "not reference-collapsing struct S1& && to struct S1& correctly");
-
 /*
  * Android's broken [u]intptr_t inttype macros are broken because its PRI*PTR
  * macros are defined as "ld", but sizeof(long) is 8 and sizeof(intptr_t)