Add Lines class to allow LinesSolver to externalize access to its vector of string

include/aoc/Lines.hpp

@@ -0,0 +1,37 @@
+// Solutions to the Advent Of Code 2024.
+// Copyright (C) 2024-2025  Stefan Müller
+//
+// This program is free software: you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free Software
+// Foundation, either version 3 of the License, or (at your option) any later
+// version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include <iostream>
+#include <string>
+#include <vector>
+
+#include <aoc/Point2.hpp>
+
+/// <summary>
+/// A vector of strings of the same length, with methods to treat it as a rectangular, two-dimensional map of char and
+/// access points on it.
+/// </summary>
+class Lines
+    : public std::vector<std::string>
+{
+public:
+    bool isInBounds(const Point2& point) const;
+    char getCharAt(const Point2& point) const;
+    void setCharAt(const Point2& point, const char value);
+};
+
+std::ostream& operator<<(std::ostream& os, const Lines& lines);

include/aoc/LinesSolver.hpp

@@ -17,6 +17,7 @@
 
 #include <vector>
 
+#include <aoc/Lines.hpp>
 #include <aoc/Point2.hpp>
 #include <aoc/Solver.hpp>
 
@@ -27,7 +28,7 @@ class LinesSolver
     LinesSolver(const int inputFileNameSuffix = 0);
     virtual void processDataLine(const std::string& line) override;
 protected:
-    std::vector<std::string> lines{};
+    Lines lines{};
     bool isInBounds(const Point2& point) const;
     char getCharAt(const Point2& point) const;
     void setCharAt(const Point2& point, const char value);