fix according to review - use fmtlib

include/dsn/utility/strings.h

@@ -49,7 +49,5 @@ char *trim_string(char *s);
 
 // calculate the md5 checksum of buffer
 std::string string_md5(const char *buffer, unsigned int length);
-
-std::string to_string_with_precision(const double double_val, const int precision);
 }
 }

src/core/core/strings.cpp

@@ -183,13 +183,5 @@ std::string string_md5(const char *buffer, unsigned length)
 
     return result;
 }
-
-std::string to_string_with_precision(const double double_val, const int precision)
-{
-    std::ostringstream out;
-    out.precision(precision);
-    out << std::fixed << double_val;
-    return out.str();
-}
 }
 }

src/dist/replication/meta_server/meta_service.cpp

@@ -35,6 +35,7 @@
 #include <sys/stat.h>
 
 #include <boost/lexical_cast.hpp>
+#include <fmt/format.h>
 
 #include <dsn/utility/factory_store.h>
 #include <dsn/dist/meta_state_service.h>
@@ -477,9 +478,9 @@ void meta_service::on_query_cluster_info(dsn::message_ex *req)
     double primary_stddev, total_stddev;
     _state->get_cluster_balance_score(primary_stddev, total_stddev);
     response.keys.push_back("primary_replica_count_stddev");
-    response.values.push_back(utils::to_string_with_precision(primary_stddev, 2));
+    response.values.push_back(fmt::format("{:.{}f}", primary_stddev, 2));
     response.keys.push_back("total_replica_count_stddev");
-    response.values.push_back(utils::to_string_with_precision(total_stddev, 2));
+    response.values.push_back(fmt::format("{:.{}f}", total_stddev, 2));
     response.err = dsn::ERR_OK;
 
     reply(req, response);