2017_22

lib/include/aocpp/Coord.hpp

@@ -80,6 +80,7 @@ auto operator*=(Coord &, std::int64_t) -> Coord &;
 template<>
 struct std::hash<aocpp::Coord>
 {
+  using is_transparent = void;
   auto operator()(aocpp::Coord const& c) const noexcept -> std::size_t {
     std::hash<std::int64_t> h;
     return h(c.x) ^ h(c.y);

lib/include/aocpp/Grid.hpp

@@ -1,11 +1,12 @@
 #ifndef AOCPP_GRID_HPP_
 #define AOCPP_GRID_HPP_
 
+#include <concepts>
 #include <iostream>
-#include <vector>
-#include <utility>
-#include <type_traits>
 #include <stdexcept>
+#include <type_traits>
+#include <utility>
+#include <vector>
 
 #include <aocpp/Coord.hpp>
 
@@ -62,8 +63,14 @@ struct Grid {
     return result;
   }
 
-  template <typename F>
-  auto each(F f = F{}) const {
+  /**
+   * @brief Apply the callback function across all elements of the grid.
+   * 
+   * @tparam F Type of callback
+   * @param f Callback function
+   */
+  template <std::invocable<Coord, char> F>
+  auto each(F f = F{}) const -> void {
     auto const h = rows.size();
     for (std::size_t y = 0; y < h; y++) {
       auto const& row = rows[y];