Added files

cpp/toolbox.hpp

@@ -0,0 +1,13 @@
+#pragma once
+#include <array>
+#include <chrono>
+#include <string>
+
+#define duration_ns(a) std::chrono::duration_cast<std::chrono::nanoseconds>(a).count()
+#define time() std::chrono::high_resolution_clock::now()
+
+std::string format_time(uint64_t) noexcept;
+std::string format_time_ns(uint64_t) noexcept;
+std::string format_byte_size(uint64_t) noexcept;
+void toolbox_unit_test() noexcept;
+std::string thousand_sep(uint64_t) noexcept;