Introduce TIdentifier

src/openrct2/core/Identifier.hpp

@@ -0,0 +1,61 @@
+/*****************************************************************************
+ * Copyright (c) 2014-2021 OpenRCT2 developers
+ *
+ * For a complete list of all authors, please refer to contributors.md
+ * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
+ *
+ * OpenRCT2 is licensed under the GNU General Public License version 3.
+ *****************************************************************************/
+
+#pragma once
+
+#include <cstdint>
+#include <cstdio>
+#include <limits>
+
+template<typename T, T TNullValue, typename TTag> class TIdentifier
+{
+    enum class ValueType : T
+    {
+        Null = TNullValue,
+    } _handle;
+
+private:
+    explicit TIdentifier(const T index)
+        : _handle{ static_cast<ValueType>(index) }
+    {
+    }
+
+public:
+    static constexpr auto Null = ValueType::Null;
+
+    TIdentifier(const ValueType other)
+        : _handle{ other }
+    {
+    }
+
+    static constexpr TIdentifier FromUnderlying(const T val) noexcept
+    {
+        return TIdentifier{ val };
+    }
+
+    constexpr T ToUnderlying() const noexcept
+    {
+        return static_cast<T>(_handle);
+    }
+
+    constexpr bool IsNull() const noexcept
+    {
+        return _handle == ValueType::Null;
+    }
+
+    constexpr bool operator==(const ValueType other) const noexcept
+    {
+        return _handle == other;
+    }
+
+    constexpr bool operator!=(const ValueType other) const noexcept
+    {
+        return _handle != other;
+    }
+};

src/openrct2/libopenrct2.vcxproj

@@ -169,6 +169,7 @@
     <ClInclude Include="core\GroupVector.hpp" />
     <ClInclude Include="core\Guard.hpp" />
     <ClInclude Include="core\Http.h" />
+    <ClInclude Include="core\Identifier.hpp" />
     <ClInclude Include="core\Imaging.h" />
     <ClInclude Include="core\IStream.hpp" />
     <ClInclude Include="core\JobPool.h" />