get_time_now 函数修复

include/toolkit.h

@@ -110,7 +110,7 @@ namespace toolkit
         return std::round(value*temp)/temp;
     }
 
-    std::string get_time_now(){
+    inline std::string get_time_now(){
         auto time_now = std::chrono::system_clock::now();
         auto now_c = std::chrono::system_clock::to_time_t(time_now);
         char buffer[32];