Codechange: Add StrongBitSet helper to simplify making a bitset from a StrongType.

src/core/CMakeLists.txt

@@ -29,6 +29,7 @@ add_files(
     string_consumer.hpp
     string_inplace.cpp
     string_inplace.hpp
+    strong_bitset_type.hpp
     strong_typedef_type.hpp
     utf8.cpp
     utf8.hpp

src/core/strong_bitset_type.hpp

@@ -0,0 +1,42 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD 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, version 2.
+ * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file strong_bitset_type.hpp Type helper for making a BitSet out of a Strong Typedef. */
+
+#ifndef STRONG_BITSET_TYPE_HPP
+#define STRONG_BITSET_TYPE_HPP
+
+#include "base_bitset_type.hpp"
+
+/**
+ * Strong bit set.
+ * @tparam Tvalue_type Type of values to wrap.
+ * @tparam Tstorage Storage type required to hold values.
+ */
+template <typename Tvalue_type, typename Tstorage, Tstorage Tmask = std::numeric_limits<Tstorage>::max()>
+class StrongBitSet : public BaseBitSet<StrongBitSet<Tvalue_type, Tstorage, Tmask>, Tvalue_type, Tstorage> {
+public:
+	constexpr StrongBitSet() : BaseClass() {}
+	constexpr StrongBitSet(Tvalue_type value) : BaseClass() { this->Set(value); }
+	explicit constexpr StrongBitSet(Tstorage data) : BaseClass(data) {}
+
+	constexpr StrongBitSet(std::initializer_list<const Tvalue_type> values) : BaseClass()
+	{
+		for (const Tvalue_type &value : values) {
+			this->Set(value);
+		}
+	}
+
+	static constexpr size_t DecayValueType(Tvalue_type value) { return value.base(); }
+
+	constexpr auto operator <=>(const StrongBitSet &) const noexcept = default;
+
+private:
+	using BaseClass = BaseBitSet<StrongBitSet<Tvalue_type, Tstorage, Tmask>, Tvalue_type, Tstorage, Tmask>;
+};
+
+#endif /* STRONG_BITSET_TYPE_HPP */