Moving headers into include/sls (#212)

slsSupportLib/include/sls/Timer.h

@@ -0,0 +1,35 @@
+#ifndef TIMER_H
+#define TIMER_H
+#include <chrono>
+#include <iostream>
+#include <string>
+
+namespace sls {
+
+class Timer {
+    using clock = std::chrono::high_resolution_clock;
+    using time_point = std::chrono::time_point<clock>;
+
+  public:
+    Timer(std::string name = "0") : t0(clock::now()), name_(name) {}
+
+    double elapsed_ms() {
+        return std::chrono::duration<double, std::milli>(clock::now() - t0)
+            .count();
+    }
+    double elapsed_s() {
+        return std::chrono::duration<double>(clock::now() - t0).count();
+    }
+    void print_elapsed() {
+        std::cout << "Timer \"" << name_ << "\": Elapsed time " << elapsed_ms()
+                  << " ms\n";
+    }
+    void restart() { t0 = clock::now(); }
+
+  private:
+    time_point t0;
+    std::string name_;
+};
+
+};     // namespace sls
+#endif // TIMER_H