public const string RUBY_DLL = @"msvcrt-ruby18";

    [DllImport(RUBY_DLL, CallingConvention = CallingConvention.Cdecl)]
    private static extern void ruby_init();

    // ... Everything in between...

    [DllImport(RUBY_DLL, CallingConvention = CallingConvention.Cdecl)]
    private static extern void ruby_finalize();