fix clang tidy
diff --git a/test/cpp/qps/qps_json_driver.cc b/test/cpp/qps/qps_json_driver.cc
index 2b81cca..1d67e79 100644
--- a/test/cpp/qps/qps_json_driver.cc
+++ b/test/cpp/qps/qps_json_driver.cc
@@ -91,7 +91,7 @@
// a map.
std::string remaining = FLAGS_per_worker_credential_types;
std::map<std::string, std::string> out;
- while (remaining.size() > 0) {
+ while (!remaining.empty()) {
size_t next_semicolon = remaining.find(';');
std::string next_entry = remaining.substr(0, next_semicolon);
if (next_semicolon == std::string::npos) {
