1 files changed, 18 insertions, 0 deletions
diff --git a/src/google/protobuf/stubs/stringpiece_unittest.cc b/src/google/protobuf/stubs/stringpiece_unittest.cc
index 9b5dae13..1cb7d12b 100644
--- a/src/google/protobuf/stubs/stringpiece_unittest.cc
+++ b/src/google/protobuf/stubs/stringpiece_unittest.cc
@@ -30,6 +30,7 @@
 #include <google/protobuf/stubs/stringpiece.h>
 
 #include <iterator>
+#include <hash_set>
 #include <map>
 #include <string>
 #include <utility>
@@ -745,6 +746,23 @@ TEST(StringPiece, Comparisons2) {
   EXPECT_TRUE(abc.ends_with("nopqrstuvwxyz"));
 }
 
+TEST(StringPiece, HashFunction) {
+  hash_set<StringPiece> set;
+
+  set.insert(StringPiece("hello"));
+  EXPECT_EQ(1, set.size());
+
+  // Insert a StringPiece of the same value again and should NOT increment
+  // size of the set.
+  set.insert(StringPiece("hello"));
+  EXPECT_EQ(1, set.size());
+
+  // Insert a StringPiece with different value and check that size of the set
+  // has been increment by one.
+  set.insert(StringPiece("world"));
+  EXPECT_EQ(2, set.size());
+}
+
 TEST(ComparisonOpsTest, StringCompareNotAmbiguous) {
   EXPECT_EQ("hello", string("hello"));
   EXPECT_LT("hello", string("world"));