Merge remote-tracking branch 'origin/v1.x' into pwm1234/rotate_on_open

include/spdlog/sinks/rotating_file_sink.h

@@ -6,7 +6,7 @@
 #pragma once
 
 #ifndef SPDLOG_H
-#error "spdlog.h must be included before this file."
+#include "spdlog/spdlog.h"
 #endif
 
 #include "spdlog/details/file_helper.h"
@@ -60,6 +60,11 @@ public:
         return fmt::to_string(w);
     }
 
+    const filename_t &filename() const
+    {
+        return file_helper_.filename();
+    }
+
 protected:
     void sink_it_(const details::log_msg &msg) override
     {