Implement day 03 part 1.

2019/src/utils.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <functional>
+#include <string_view>
+
+namespace aoc2019 {
+
+    template<typename T>
+    void combine_hash(std::size_t& seed, const T& o) {
+        // Algorithm taken from boost::combine_hash.
+        std::hash<T> hash{};
+        seed ^= hash(o) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+    }
+
+    std::string_view strtok(std::string_view &str, char token = ',');
+}