init repo.

src/units/timestamp.cc

@@ -0,0 +1,24 @@
+#include "sled/units/timestamp.h"
+#include <sstream>
+
+namespace sled {
+std::string
+ToString(Timestamp value)
+{
+    char buf[64];
+    std::stringstream ss;
+    if (value.IsPlusInfinity()) {
+        ss << "+inf ms";
+    } else if (value.IsMinusInfinity()) {
+        ss << "-inf ms";
+    } else {
+        if (value.us() == 0 || (value.us() % 1000) != 0)
+            ss << value.us() << " us";
+        else if (value.ms() % 1000 != 0)
+            ss << value.ms() << " ms";
+        else
+            ss << value.seconds() << " s";
+    }
+    return ss.str();
+}
+}// namespace sled