grids

lib/include/aocpp/Coord.hpp

@@ -16,7 +16,6 @@ struct Coord {
   auto operator<=>(const Coord&) const = default;
 };
 
-
 auto Draw(std::ostream & out, std::map<Coord, std::int64_t> image) -> void;
 
 /// Move one unit up

lib/include/aocpp/Grid.hpp

@@ -0,0 +1,43 @@
+#ifndef AOCPP_GRID_HPP_
+#define AOCPP_GRID_HPP_
+
+#include <iostream>
+#include <vector>
+#include <utility>
+#include <type_traits>
+
+#include <aocpp/Coord.hpp>
+
+namespace aocpp {
+
+struct Grid {
+  std::vector<std::string> rows;
+
+  auto operator[](Coord c)       -> char& { return rows[c.y][c.x]; }
+  auto operator[](Coord c) const -> char  { return rows[c.y][c.x]; }
+
+  static auto Parse(std::istream & in) -> Grid {
+    Grid result;
+    std::string line;
+    while (std::getline(in, line)) {
+      result.rows.emplace_back(std::move(line));
+    }
+    return {result};
+  }
+
+  template <typename F>
+  auto each(F f = F{}) const {
+    auto const h = rows.size();
+    for (std::size_t y = 0; y < h; y++) {
+      auto const& row = rows[y];
+      auto const w = row.size();
+      for (std::size_t x = 0; x < w; x++) {
+        f(Coord{static_cast<std::int64_t>(x), static_cast<std::int64_t>(y)}, row[x]);
+      }
+    }
+  }
+};
+
+}
+
+#endif