Just in case you are maintaining Delphi code for several older versions of Delphi: Be aware that the declarations of NativeInt and NativeUInt are wrong in some of them. Delphi versionSizeOf(Native(U)Int) Win32SizeOf(Native(U)Int) Win64 1 to 6not availablenot available 7 to 20078 ← this is wrongnot available 2009 to XE4not available XE2 to XE848 10.x48 I … Continue reading NativeInt / NativeUInt type in various Delphi versions