[ADT] Make iterable SmallVector template overrides more specific

Summary:
This prevents the iterator overrides from being selected in
the case where non-iterator types are used as arguments, which
is of particular importance in cases where other overrides with
identical types exist.

Reviewers: dblaikie, bkramer, rafael

Subscribers: llvm-commits, efriedma

Differential Revision: https://reviews.llvm.org/D33919

llvm-svn: 305105

llvm/include/llvm/ADT/SmallVector.h

@@ -388,7 +388,10 @@ public:
   void swap(SmallVectorImpl &RHS);
 
   /// Add the specified range to the end of the SmallVector.
-  template<typename in_iter>
+  template <typename in_iter,
+            typename = typename std::enable_if<std::is_convertible<
+                typename std::iterator_traits<in_iter>::iterator_category,
+                std::input_iterator_tag>::value>::type>
   void append(in_iter in_start, in_iter in_end) {
     size_type NumInputs = std::distance(in_start, in_end);
     // Grow allocated space if needed.
@@ -426,7 +429,11 @@ public:
     std::uninitialized_fill(this->begin(), this->end(), Elt);
   }
 
-  template <typename in_iter> void assign(in_iter in_start, in_iter in_end) {
+  template <typename in_iter,
+            typename = typename std::enable_if<std::is_convertible<
+                typename std::iterator_traits<in_iter>::iterator_category,
+                std::input_iterator_tag>::value>::type>
+  void assign(in_iter in_start, in_iter in_end) {
     clear();
     append(in_start, in_end);
   }
@@ -579,7 +586,10 @@ public:
     return I;
   }
 
-  template<typename ItTy>
+  template <typename ItTy,
+            typename = typename std::enable_if<std::is_convertible<
+                typename std::iterator_traits<ItTy>::iterator_category,
+                std::input_iterator_tag>::value>::type>
   iterator insert(iterator I, ItTy From, ItTy To) {
     // Convert iterator to elt# to avoid invalidating iterator when we reserve()
     size_t InsertElt = I - this->begin();
@@ -860,7 +870,10 @@ public:
     this->assign(Size, Value);
   }
 
-  template<typename ItTy>
+  template <typename ItTy,
+            typename = typename std::enable_if<std::is_convertible<
+                typename std::iterator_traits<ItTy>::iterator_category,
+                std::input_iterator_tag>::value>::type>
   SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(N) {
     this->append(S, E);
   }

llvm/unittests/ADT/SmallVectorTest.cpp

@@ -209,6 +209,22 @@ typedef ::testing::Types<SmallVector<Constructable, 0>,
                          > SmallVectorTestTypes;
 TYPED_TEST_CASE(SmallVectorTest, SmallVectorTestTypes);
 
+// Constructor test.
+TYPED_TEST(SmallVectorTest, ConstructorNonIterTest) {
+  SCOPED_TRACE("ConstructorTest");
+  this->theVector = SmallVector<Constructable, 2>(2, 2);
+  this->assertValuesInOrder(this->theVector, 2u, 2, 2);
+}
+
+// Constructor test.
+TYPED_TEST(SmallVectorTest, ConstructorIterTest) {
+  SCOPED_TRACE("ConstructorTest");
+  int arr[] = {1, 2, 3};
+  this->theVector =
+      SmallVector<Constructable, 4>(std::begin(arr), std::end(arr));
+  this->assertValuesInOrder(this->theVector, 3u, 1, 2, 3);
+}
+
 // New vector test.
 TYPED_TEST(SmallVectorTest, EmptyVectorTest) {
   SCOPED_TRACE("EmptyVectorTest");
@@ -415,6 +431,33 @@ TYPED_TEST(SmallVectorTest, AppendRepeatedTest) {
   this->assertValuesInOrder(this->theVector, 3u, 1, 77, 77);
 }
 
+// Append test
+TYPED_TEST(SmallVectorTest, AppendNonIterTest) {
+  SCOPED_TRACE("AppendRepeatedTest");
+
+  this->theVector.push_back(Constructable(1));
+  this->theVector.append(2, 7);
+  this->assertValuesInOrder(this->theVector, 3u, 1, 7, 7);
+}
+
+TYPED_TEST(SmallVectorTest, AppendRepeatedNonForwardIterator) {
+  SCOPED_TRACE("AppendRepeatedTest");
+
+  struct output_iterator {
+    typedef std::output_iterator_tag iterator_category;
+    typedef int value_type;
+    typedef int difference_type;
+    typedef value_type *pointer;
+    typedef value_type &reference;
+    operator int() { return 2; }
+    operator Constructable() { return 7; }
+  };
+
+  this->theVector.push_back(Constructable(1));
+  this->theVector.append(output_iterator(), output_iterator());
+  this->assertValuesInOrder(this->theVector, 3u, 1, 7, 7);
+}
+
 // Assign test
 TYPED_TEST(SmallVectorTest, AssignTest) {
   SCOPED_TRACE("AssignTest");
@@ -434,6 +477,15 @@ TYPED_TEST(SmallVectorTest, AssignRangeTest) {
   this->assertValuesInOrder(this->theVector, 3u, 1, 2, 3);
 }
 
+// Assign test
+TYPED_TEST(SmallVectorTest, AssignNonIterTest) {
+  SCOPED_TRACE("AssignTest");
+
+  this->theVector.push_back(Constructable(1));
+  this->theVector.assign(2, 7);
+  this->assertValuesInOrder(this->theVector, 2u, 7, 7);
+}
+
 // Move-assign test
 TYPED_TEST(SmallVectorTest, MoveAssignTest) {
   SCOPED_TRACE("MoveAssignTest");
@@ -532,6 +584,15 @@ TYPED_TEST(SmallVectorTest, InsertRepeatedTest) {
   this->assertValuesInOrder(this->theVector, 6u, 1, 16, 16, 2, 3, 4);
 }
 
+TYPED_TEST(SmallVectorTest, InsertRepeatedNonIterTest) {
+  SCOPED_TRACE("InsertRepeatedTest");
+
+  this->makeSequence(this->theVector, 1, 4);
+  Constructable::reset();
+  auto I = this->theVector.insert(this->theVector.begin() + 1, 2, 7);
+  EXPECT_EQ(this->theVector.begin() + 1, I);
+  this->assertValuesInOrder(this->theVector, 6u, 1, 7, 7, 2, 3, 4);
+}
 
 TYPED_TEST(SmallVectorTest, InsertRepeatedAtEndTest) {
   SCOPED_TRACE("InsertRepeatedTest");