Update matrix_constraint.hpp

Author: XuhuaHuang

IntroductionToRobotics/matrix_constraint.hpp

@@ -7,7 +7,7 @@
  *
  * $ g++ matrix_constraint.hpp -std=c++2b -Wall -Wextra -O3 -Wno-pragma-once-outside-header
  *
- * @copyright ueg (c) 2023
+ * @copyright Copyright (c) 2023
  *
  */
 
@@ -17,15 +17,58 @@
 
 #include <array>
 #include <concepts>
+#include <iterator>
+#include <ranges>
+#include <vector>
+
+
+namespace robotics
+{
 
 template<typename T, std::size_t M, std::size_t N>
 concept matrix = requires (std::array<std::array<T, N>, M> matrix) {
-    {
-        matrix.size()
-    } -> std::convertible_to<size_t>;
-    {
-        matrix[0].size()
-    } -> std::convertible_to<size_t>;
+    { matrix.size() } -> std::convertible_to<size_t>;
+    { matrix[0].size() } -> std::convertible_to<size_t>;
+};
+
+template<typename R, typename T>
+concept weak_matrix = std::convertible_to<std::ranges::range_reference_t<std::ranges::range_reference_t<R>>, T>;
+
+template<typename T>
+concept random_access_container = requires (T container) {
+    typename T::value_type;
+    typename T::iterator;
+    typename T::const_iterator;
+
+    // check if the container has begin() and end() member functions
+    { container.begin() } -> std::same_as<typename T::iterator>;
+    { container.end() } -> std::same_as<typename T::iterator>;
+
+    // check if the container supports random access
+    requires std::random_access_iterator<typename T::iterator>;
+
+    // check if the container has size() member function
+    { container.size() } -> std::integral;
+
+    // check if the container has the subscript operator (operator[])
+    requires requires (T container, typename T::size_type i) {
+        { container[i] } -> std::same_as<typename T::reference>;
+    };
 };
 
+// Concept to constrain a 2D matrix
+template<typename T>
+concept random_access_matrix =
+    random_access_container<T> && random_access_container<typename T::value_type> && requires (T mat) {
+        // Optional: Add additional constraints like ensuring the matrix has
+        // rows of equal size
+        { mat.size() > 0 } -> std::convertible_to<bool>;
+        { mat[0].size() > 0 } -> std::convertible_to<bool>;
+    };
+
+// Example usage with a vector of vectors (2D matrix)
+static_assert(random_access_matrix<std::vector<std::vector<int>>>);
+
+} // namespace robotics
+
 #endif // !MATRIX_CONSTRAINT_HPP