check if logger already exists in the registry before creating it

include/spdlog/details/registry.h

@@ -33,7 +33,9 @@ public:
     void register_logger(std::shared_ptr<logger> logger)
     {
         std::lock_guard<Mutex> lock(_mutex);
-        register_logger_impl(logger);
+		auto logger_name = logger->name();
+		throw_if_exists(logger_name);		
+		_loggers[logger_name] = logger;
     }
 
 
@@ -47,12 +49,9 @@ public:
     template<class It>
     std::shared_ptr<logger> create(const std::string& logger_name, const It& sinks_begin, const It& sinks_end)
     {        
-
-        std::shared_ptr<logger> new_logger;
-
         std::lock_guard<Mutex> lock(_mutex);
-
-
+		throw_if_exists(logger_name);
+		std::shared_ptr<logger> new_logger;
         if (_async_mode)
             new_logger = std::make_shared<async_logger>(logger_name, sinks_begin, sinks_end, _async_q_size, _overflow_policy, _worker_warmup_cb, _flush_interval_ms);
         else
@@ -62,7 +61,8 @@ public:
             new_logger->set_formatter(_formatter);
 
         new_logger->set_level(_level);
-        register_logger_impl(new_logger);
+		//Add to registry
+		_loggers[logger_name] = new_logger;
         return new_logger;
     }
 
@@ -135,16 +135,15 @@ public:
     }
 
 private:    
-    void register_logger_impl(std::shared_ptr<logger> logger)
-    {
-        auto logger_name = logger->name();
-        if (_loggers.find(logger_name) != std::end(_loggers))
-            throw spdlog_ex("logger with name " + logger_name + " already exists");
-        _loggers[logger->name()] = logger;
-    }
     registry_t<Mutex>() {}
     registry_t<Mutex>(const registry_t<Mutex>&) = delete;
     registry_t<Mutex>& operator=(const registry_t<Mutex>&) = delete;
+
+	void throw_if_exists(const std::string &logger_name)
+	{
+		if (_loggers.find(logger_name) != _loggers.end())
+			throw spdlog_ex("logger with name '" + logger_name + "' already exists");
+	}
     Mutex _mutex;
     std::unordered_map <std::string, std::shared_ptr<logger>> _loggers;
     formatter_ptr _formatter;