Move Monoclock and strerror out of drvutil

luprex/cpp/drv/osdrvutil.hpp

@@ -0,0 +1,23 @@
+#ifndef OSDRVUTIL_HPP
+#define OSDRVUTIL_HPP
+
+#include <string>
+
+namespace drvutil {
+
+// Get a system error message, in an OS-independent manner.
+//
+std::string strerror_str(int errnum);
+
+// Get the amount of time elapsed since program start.
+//
+// This is guaranteed to be monotonically increasing.  It is not
+// guaranteed to be accurate.  Error could gradually accumulate over
+// time.
+//
+double get_monotonic_clock();
+
+} // namespace drvutil
+
+#endif // OSDRVUTIL_HPP
+