From 7eded94ac1a17c18e21210a7fce31592c6a0b576 Mon Sep 17 00:00:00 2001
From: "Timur A. Fatkhullin" <timur@sao.ru>
Date: Mon, 7 Jul 2025 17:47:54 +0300
Subject: [PATCH] ...

---
 cxx/mcc_mount_astro_erfa.h |   2 +-
 cxx/mcc_mount_astrom.h     |   2 +-
 cxx/mcc_mount_hardware.h   | 113 +++++++++++++++++++++++++++++++++++++
 cxx/mcc_traits.h           |  13 +++++
 4 files changed, 128 insertions(+), 2 deletions(-)
 create mode 100644 cxx/mcc_mount_hardware.h

diff --git a/cxx/mcc_mount_astro_erfa.h b/cxx/mcc_mount_astro_erfa.h
index 16702fa..cd43376 100644
--- a/cxx/mcc_mount_astro_erfa.h
+++ b/cxx/mcc_mount_astro_erfa.h
@@ -95,7 +95,7 @@ public:
 
     virtual ~MccMountAstromEngineERFA() = default;
 
-    void updateState(engine_state_t state)
+    void setState(engine_state_t state)
     {
         std::lock_guard lock{_stateMutex};
 
diff --git a/cxx/mcc_mount_astrom.h b/cxx/mcc_mount_astrom.h
index db14a50..610aa18 100644
--- a/cxx/mcc_mount_astrom.h
+++ b/cxx/mcc_mount_astrom.h
@@ -32,7 +32,7 @@ concept mcc_astrom_engine_c = requires(T t, const T t_const) {
     typename T::refract_result_t;
 
 
-    { t.updateState(std::declval<typename T::engine_state_t>()) };
+    { t.setState(std::declval<typename T::engine_state_t>()) };
 
     { t_const.getState() } -> std::same_as<typename T::engine_state_t>;
 
diff --git a/cxx/mcc_mount_hardware.h b/cxx/mcc_mount_hardware.h
new file mode 100644
index 0000000..91f398f
--- /dev/null
+++ b/cxx/mcc_mount_hardware.h
@@ -0,0 +1,113 @@
+#pragma once
+
+/*  MOUNT CONTROL COMPONENTS LIBRARY  */
+
+/*  MOUNT HARDWARE CONCEPTS   */
+
+
+#include <utility>
+#include "mcc_traits.h"
+
+namespace mcc
+{
+
+namespace traits
+{
+
+// encoder basic concept (e.g. mount axis encoder or motor shaft one)
+template <typename T>
+concept mcc_hw_encoder_c = requires(T t, const T t_const) {
+    typename T::error_t;
+
+    typename T::time_point_t;
+    typename T::coord_t;
+    typename T::speed_t;
+    typename T::accel_t;
+    // typename T::high_order_deriv_t;
+
+    requires requires(typename T::state_t st) {
+        std::same_as<decltype(st.time), typename T::time_point_t>;
+        std::same_as<decltype(st.pos), typename T::coord_t>;
+        std::same_as<decltype(st.speed), typename T::speed_t>;
+        std::same_as<decltype(st.accel), typename T::accel_t>;
+        // std::same_as<decltype(st.high_order), typename T::high_order_deriv_t>;
+    };
+
+    { t_const.id() } -> mcc_formattable;
+
+    { t.getState(std::declval<typename T::state_t&>()) } -> std::same_as<typename T::error_t>;
+};
+
+
+template <typename T>
+concept mcc_hw_motor_c = requires(T t, const T t_const) {
+    typename T::coord_t;
+    typename T::speed_t;
+    typename T::accel_t;
+
+    requires requires(typename T::pos_t st) {
+        std::same_as<decltype(st.pos), typename T::coord_t>;
+        std::same_as<decltype(st.speed), typename T::speed_t>;  // means maximal allowed speed
+        std::same_as<decltype(st.accel), typename T::accel_t>;  // means a maximal allowed acceleration (jerk)
+    };
+
+
+    { t_const.id() } -> mcc_formattable;
+
+    { t.rotate(std::declval<typename T::pos_t>()) } -> std::same_as<typename T::error_t>;
+
+    { t.stop() } -> std::same_as<typename T::error_t>;
+};
+
+
+
+namespace details
+{
+template <typename T>
+concept mcc_tuple_enc_ref_c = mcc_tuple_c<T> && requires(T t) {
+    []<template <typename...> typename TT, mcc_hw_encoder_c... Ts>(TT<Ts & ...>) {}(t);
+};
+
+template <typename T>
+concept mcc_tuple_enc_cref_c = mcc_tuple_c<T> && requires(T t) {
+    []<template <typename...> typename TT, mcc_hw_encoder_c... Ts>(TT<const Ts & ...>) {}(t);
+};
+
+template <typename T>
+concept mcc_tuple_motor_ref_c = mcc_tuple_c<T> && requires(T t) {
+    []<template <typename...> typename TT, mcc_hw_motor_c... Ts>(TT<Ts & ...>) {}(t);
+};
+
+
+template <typename T>
+concept mcc_hw_enc_lref_c = std::is_lvalue_reference_v<T> && mcc_hw_encoder_c<std::remove_cvref_t<T>>;
+
+
+template <typename T>
+concept mcc_hw_motor_lref_c = std::is_lvalue_reference_v<T> && mcc_hw_motor_c<std::remove_cvref_t<T>>;
+
+}  // namespace details
+
+
+// a very generic mount hardware concept
+template <typename T>
+concept mcc_mount_hardware_c = requires(T t, const T t_const) {
+    { t_const.id() } -> mcc_formattable;
+
+    // access to encoders
+    { t_const.encoders() } -> details::mcc_tuple_enc_cref_c;
+    { t.encoders() } -> details::mcc_tuple_enc_ref_c;
+
+    { t.encoderPosX() } -> details::mcc_hw_enc_lref_c;
+    { t.encoderPosY() } -> details::mcc_hw_enc_lref_c;
+
+    // access to motors
+    { t.motors() } -> details::mcc_tuple_motor_ref_c;
+
+    { t.motorX() } -> details::mcc_hw_motor_lref_c;
+    { t.motorY() } -> details::mcc_hw_motor_lref_c;
+};
+
+}  // namespace traits
+
+}  // namespace mcc
diff --git a/cxx/mcc_traits.h b/cxx/mcc_traits.h
index a1b5e9a..a3804d4 100644
--- a/cxx/mcc_traits.h
+++ b/cxx/mcc_traits.h
@@ -145,6 +145,19 @@ template <typename T, typename... CtorArgTs>
 concept mcc_output_arg_c = !std::is_const_v<std::remove_reference_t<T>> && std::is_lvalue_reference_v<T> &&
                            std::constructible_from<std::remove_reference_t<T>, CtorArgTs...>;
 
+
+
+// std::tuple or std::pair
+template <typename T>
+concept mcc_tuple_c = requires {
+    requires requires {
+        []<typename... Ts>(std::type_identity<std::tuple<Ts...>>) {}(std::type_identity<std::remove_cvref_t<T>>());
+    } || requires {
+        []<typename T1, typename T2>(std::type_identity<std::pair<T1, T2>>) {
+        }(std::type_identity<std::remove_cvref_t<T>>());
+    };
+};
+
 namespace details
 {