sync() after write to avoid losing file data on power off.

PiPedalCommon/src/include/ofstream_synced.hpp

@@ -0,0 +1,26 @@
+
+#pragma once
+
+#include <fstream>
+
+namespace pipedal
+{
+    void FileSystemSync();
+
+    class ofstream_synced : public std::ofstream
+    {
+    public:
+        ofstream_synced() {}
+
+        explicit ofstream_synced(const std::string &filename, ios_base::openmode mode = ios_base::out)
+            : std::ofstream(filename, mode)
+        {
+        }
+        explicit ofstream_synced(const char *filename, ios_base::openmode mode = ios_base::out)
+            : std::ofstream(filename, mode)
+        {
+        }
+        ~ofstream_synced();
+    };
+
+}