SERVER-54352 std::string += StringData

2 files changed, 13 insertions, 0 deletions

diff --git a/src/mongo/base/string_data.h b/src/mongo/base/string_data.h
index 10c6758689e..c040c98cfb5 100644
--- a/src/mongo/base/string_data.h
+++ b/src/mongo/base/string_data.h
@@ -321,6 +321,12 @@ inline bool StringData::endsWith(StringData suffix) const {
     return substr(thisSize - suffixSize) == suffix;
 }
 
+inline std::string& operator+=(std::string& lhs, StringData rhs) {
+    if (!rhs.empty())
+        lhs.append(rhs.rawData(), rhs.size());
+    return lhs;
+}
+
 inline std::string operator+(std::string lhs, StringData rhs) {
     if (!rhs.empty())
         lhs.append(rhs.rawData(), rhs.size());
diff --git a/src/mongo/base/string_data_test.cpp b/src/mongo/base/string_data_test.cpp
index c31d376c5b4..a809ddf8f95 100644
--- a/src/mongo/base/string_data_test.cpp
+++ b/src/mongo/base/string_data_test.cpp
@@ -448,5 +448,12 @@ TEST(Ostream, StringDataMatchesStdString) {
     }
 }
 
+TEST(StringData, PlusEq) {
+    auto str = std::string("hello ");
+    auto& ret = str += "world"_sd;
+    ASSERT_EQ(str, "hello world");
+    ASSERT_EQ(&ret, &str);
+}
+
 }  // namespace
 }  // namespace mongo