> unless they completely re-wrote the whole calculator app (for which there seems to be no reason).
That's actually exactly what happened. The original calc.exe (in all versions up to Windows 8.1) came from Windows 1.0, in plain C, very seldomly updated over the years.
The one in Windows 10 is totally rewritten in C++ using the "Universal Windows Platform" as an API rather than classic Win32.
That's actually exactly what happened. The original calc.exe (in all versions up to Windows 8.1) came from Windows 1.0, in plain C, very seldomly updated over the years.
The one in Windows 10 is totally rewritten in C++ using the "Universal Windows Platform" as an API rather than classic Win32.