...

mcc/mcc_generics.h

@@ -420,6 +420,14 @@ concept mcc_hardware_c = requires(T t, const T t_const) {
 
     { t_const.hardwareName() } -> std::formattable<char>;
 
+    // the 'T' class must contain static constexpr member of 'MccMountType' type
+    requires std::same_as<decltype(T::mountType), const MccMountType>;
+    []() {
+        static constexpr MccMountType val = T::mountType;
+        return val;
+    }();  // to ensure 'mountType' can be used in compile-time context
+
+
     // a type that defines at least HW_MOVE_STOPPED, HW_MOVE_SLEWING, HW_MOVE_ADJUSTING, HW_MOVE_TRACKING
     // and HW_MOVE_GUIDING compile-time constants. The main purpose of this type is a
     // possible tunning of hardware hardwareSetState-related commands and detect stop-state
@@ -657,6 +665,13 @@ struct mcc_telemetry_interface_t {
         std::forward<SelfT>(self).targetToMountDiff(pair_kind, dx, dy);
     }
 
+    // compute distance between target and actual mount celestial points
+    template <std::derived_from<mcc_telemetry_interface_t> SelfT>
+    RetT targetToMountDist(this SelfT&& self, mcc_angle_c auto* dist)
+    {
+        std::forward<SelfT>(self).targetToMountDist(dist);
+    }
+
 protected:
     mcc_telemetry_interface_t() = default;
 };