[ADT] add equality operator for SmallSet

Makes it easier to migrate existing code that uses std::set.

Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D69417

1 files changed, 25 insertions, 0 deletions

diff --git a/llvm/unittests/ADT/SmallSetTest.cpp b/llvm/unittests/ADT/SmallSetTest.cpp
index 8fb78b01f44..06682ce823d 100644
--- a/llvm/unittests/ADT/SmallSetTest.cpp
+++ b/llvm/unittests/ADT/SmallSetTest.cpp
@@ -142,3 +142,28 @@ TEST(SmallSetTest, IteratorIncMoveCopy) {
   Iter = std::move(Iter2);
   EXPECT_EQ("str 0", *Iter);
 }
+
+TEST(SmallSetTest, EqualityComparisonTest) {
+  SmallSet<int, 8> s1small;
+  SmallSet<int, 10> s2small;
+  SmallSet<int, 3> s3large;
+  SmallSet<int, 8> s4large;
+
+  for (int i = 1; i < 5; i++) {
+    s1small.insert(i);
+    s2small.insert(5 - i);
+    s3large.insert(i);
+  }
+  for (int i = 1; i < 11; i++)
+    s4large.insert(i);
+
+  EXPECT_EQ(s1small, s1small);
+  EXPECT_EQ(s3large, s3large);
+
+  EXPECT_EQ(s1small, s2small);
+  EXPECT_EQ(s1small, s3large);
+  EXPECT_EQ(s2small, s3large);
+
+  EXPECT_NE(s1small, s4large);
+  EXPECT_NE(s4large, s3large);
+}