[llvm] r283803 - Revert "Disallow ArrayRef assignment from temporaries."

[Zachary Turner via llvm-commits]

Author: zturner
Date: Mon Oct 10 16:36:23 2016
New Revision: 283803

URL: http://llvm.org/viewvc/llvm-project?rev=283803&view=rev
Log:
Revert "Disallow ArrayRef assignment from temporaries."

This reverts commit r283798, as it causes static asserts on
MSVC 2015 with the following errors:

ArrayRefTest.cpp(38): error C2338: Assigning from single prvalue element
ArrayRefTest.cpp(41): error C2338: Assigning from single xvalue element
ArrayRefTest.cpp(47): error C2338: Assigning from an initializer list

Modified:
    llvm/trunk/include/llvm/ADT/ArrayRef.h
    llvm/trunk/unittests/ADT/ArrayRefTest.cpp

Modified: llvm/trunk/include/llvm/ADT/ArrayRef.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/ArrayRef.h?rev=283803&r1=283802&r2=283803&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/ArrayRef.h (original)
+++ llvm/trunk/include/llvm/ADT/ArrayRef.h Mon Oct 10 16:36:23 2016
@@ -219,22 +219,6 @@ namespace llvm {
       return Data[Index];
     }
 
-    /// Disallow accidental assignment from a temporary.
-    ///
-    /// The declaration here is extra complicated so that "arrayRef = {}"
-    /// continues to select the move assignment operator.
-    template <typename U>
-    typename std::enable_if<std::is_same<U, T>::value, ArrayRef<T>>::type &
-    operator=(U &&Temporary) = delete;
-
-    /// Disallow accidental assignment from a temporary.
-    ///
-    /// The declaration here is extra complicated so that "arrayRef = {}"
-    /// continues to select the move assignment operator.
-    template <typename U>
-    typename std::enable_if<std::is_same<U, T>::value, ArrayRef<T>>::type &
-    operator=(std::initializer_list<U>) = delete;
-
     /// @}
     /// @name Expensive Operations
     /// @{

Modified: llvm/trunk/unittests/ADT/ArrayRefTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/ArrayRefTest.cpp?rev=283803&r1=283802&r2=283803&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/ArrayRefTest.cpp (original)
+++ llvm/trunk/unittests/ADT/ArrayRefTest.cpp Mon Oct 10 16:36:23 2016
@@ -31,21 +31,6 @@ static_assert(
     !std::is_convertible<ArrayRef<volatile int *>, ArrayRef<int *>>::value,
     "Removing volatile");
 
-// Check that we can't accidentally assign a temporary location to an ArrayRef.
-// (Unfortunately we can't make use of the same thing with constructors.)
-static_assert(
-    !std::is_assignable<ArrayRef<int *>, int *>::value,
-    "Assigning from single prvalue element");
-static_assert(
-    !std::is_assignable<ArrayRef<int *>, int * &&>::value,
-    "Assigning from single xvalue element");
-static_assert(
-    std::is_assignable<ArrayRef<int *>, int * &>::value,
-    "Assigning from single lvalue element");
-static_assert(
-    !std::is_assignable<ArrayRef<int *>, std::initializer_list<int *>>::value,
-    "Assigning from an initializer list");
-
 namespace {
 
 TEST(ArrayRefTest, AllocatorCopy) {
@@ -176,14 +161,6 @@ TEST(ArrayRefTest, InitializerList) {
   ArgTest12({1, 2});
 }
 
-TEST(ArrayRefTest, EmptyInitializerList) {
-  ArrayRef<int> A = {};
-  EXPECT_TRUE(A.empty());
-
-  A = {};
-  EXPECT_TRUE(A.empty());
-}
-
 // Test that makeArrayRef works on ArrayRef (no-op)
 TEST(ArrayRefTest, makeArrayRef) {
   static const int A1[] = {1, 2, 3, 4, 5, 6, 7, 8};