[llvm] [ADT] Add C++17-style insert_or_assign for DenseMap (PR #94151)

[via llvm-commits]

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@@ -484,21 +461,55 @@ TEST(DenseMapCustomTest, ReserveTest) {
     DenseMap<int, CountCopyAndMove> Map;
     Map.reserve(Size);
     unsigned MemorySize = Map.getMemorySize();
-    CountCopyAndMove::Copy = 0;
-    CountCopyAndMove::Move = 0;
+    CountCopyAndMove::ResetCounts();
     for (int i = 0; i < Size; ++i)
       Map.insert(std::pair<int, CountCopyAndMove>(std::piecewise_construct,
                                                   std::forward_as_tuple(i),
                                                   std::forward_as_tuple()));
     // Check that we didn't grow
     EXPECT_EQ(MemorySize, Map.getMemorySize());
     // Check that move was called the expected number of times
-    EXPECT_EQ(Size, CountCopyAndMove::Move);
+    EXPECT_EQ(Size, CountCopyAndMove::TotalMoves());
     // Check that no copy occurred
-    EXPECT_EQ(0, CountCopyAndMove::Copy);
+    EXPECT_EQ(0, CountCopyAndMove::TotalCopies());
   }
 }
 
+TEST(DenseMapCustomTest, InsertOrAssignTest) {
+  DenseMap<int, CountCopyAndMove> Map;
+  CountCopyAndMove::ResetCounts();
+
+  CountCopyAndMove val1(1);
+  auto try0 = Map.insert_or_assign(0, val1);
+  EXPECT_TRUE(try0.second);
+  EXPECT_EQ(0, CountCopyAndMove::TotalMoves());
+  EXPECT_EQ(1, CountCopyAndMove::CopyConstructions);
+  EXPECT_EQ(0, CountCopyAndMove::CopyAssignments);
+
+  auto try1 = Map.insert_or_assign(0, val1);
+  EXPECT_FALSE(try1.second);
+  EXPECT_EQ(0, CountCopyAndMove::TotalMoves());
+  EXPECT_EQ(1, CountCopyAndMove::CopyConstructions);
+  EXPECT_EQ(1, CountCopyAndMove::CopyAssignments);
+
+  int key2 = 2;
+  CountCopyAndMove val2(2);
+  auto try2 = Map.insert_or_assign(key2, std::move(val2));
+  EXPECT_TRUE(try2.second);
+  EXPECT_EQ(1, CountCopyAndMove::MoveConstructions);
+  EXPECT_EQ(0, CountCopyAndMove::MoveAssignments);
+  EXPECT_EQ(1, CountCopyAndMove::CopyConstructions);
+  EXPECT_EQ(1, CountCopyAndMove::CopyAssignments);
+
+  CountCopyAndMove val3(3);
+  auto try3 = Map.insert_or_assign(key2, std::move(val3));
+  EXPECT_FALSE(try3.second);
+  EXPECT_EQ(1, CountCopyAndMove::MoveConstructions);
+  EXPECT_EQ(1, CountCopyAndMove::MoveAssignments);
+  EXPECT_EQ(1, CountCopyAndMove::CopyConstructions);
+  EXPECT_EQ(1, CountCopyAndMove::CopyAssignments);
+}
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c8ef wrote:

Done.

https://github.com/llvm/llvm-project/pull/94151