Fixed issue #881

include/spdlog/details/logger_impl.h

@@ -293,7 +293,7 @@ inline void spdlog::logger::set_error_handler(spdlog::log_err_handler err_handle
     err_handler_ = std::move(err_handler);
 }
 
-inline spdlog::log_err_handler spdlog::logger::error_handler()
+inline spdlog::log_err_handler spdlog::logger::error_handler() const
 {
     return err_handler_;
 }

include/spdlog/logger.h

@@ -140,7 +140,7 @@ public:
 
     // error handler
     void set_error_handler(log_err_handler err_handler);
-    log_err_handler error_handler();
+    log_err_handler error_handler() const;
 
     // create new logger with same sinks and configuration.
     virtual std::shared_ptr<logger> clone(std::string logger_name);