fix code review comments (rusefi#16)

Author: kifir23917

util/include/rusefi/rusefi_time_types.h

@@ -28,7 +28,7 @@ static_assert(sizeof(efidurus_t) == 8);
 /**
  * 64 bit time in microseconds (1/1_000_000 of a second), since boot
  */
-using efitimeus_t = std::chrono::time_point<std::chrono::system_clock, efidurus_t>;
+using efitimeus_t = std::chrono::time_point<std::chrono::steady_clock, efidurus_t>;
 static_assert(sizeof(efitimeus_t) == 8);
 
 // time in seconds
@@ -59,19 +59,24 @@ efitick_t getTimeNowNt();
 #define US_PER_SECOND_F 1000000.0
 #define US_PER_SECOND_LL 1000000LL
 
-template<typename arithmetic_type> constexpr efitimeus_t USOF(const arithmetic_type& us) {
-  static_assert(std::is_arithmetic_v<arithmetic_type>);
-  return efitimeus_t(efidurus_t(static_cast<efitimeus_t::rep>(us)));
+template <typename T> concept numeric = std::integral<T> || std::floating_point<T>;
+
+constexpr numeric auto MS2US(numeric auto ms_time) {
+  return ms_time * 1000;
 }
 
-constexpr float MS2US(const float& timems) {
-  return timems * 1000;
+constexpr numeric auto US2MS(numeric auto timeus) {
+  return timeus / 1000;
 }
 
 constexpr efitimeus_t::rep US2MS(const efitimeus_t& timeus) {
-  return timeus.time_since_epoch().count() / 1000;
+ return timeus.time_since_epoch().count() / 1000;
 }
 
-constexpr float US2MS(const float& timeus) {
-  return timeus / 1000;
+constexpr efitimeus_t USOF(std::integral auto us) {
+ return efitimeus_t(efidurus_t(us));
+}
+
+constexpr efitimeus_t::rep COUNTOF(const efitimeus_t& us) {
+ return us.time_since_epoch().count();
 }