WIP: unreachable?

src/catch2/internal/catch_unreachable.cpp

@@ -0,0 +1,17 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#include <catch2/internal/catch_unreachable.hpp>
+
+namespace Catch {
+    namespace Detail {
+
+        void unreachable(){}
+
+    }
+} // end namespace Catch

src/catch2/internal/catch_unreachable.hpp

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+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+#ifndef CATCH_UNREACHABLE_HPP_INCLUDED
+#define CATCH_UNREACHABLE_HPP_INCLUDED
+
+namespace Catch {
+
+    namespace Detail {
+        // TODO: explain
+        [[noreturn]] void unreachable();
+
+    }
+
+} // end namespace Catch
+
+#endif // CATCH_UNREACHABLE_HPP_INCLUDED