Re: 80286 protected mode

On 15/10/2024 23:26, Stefan Monnier wrote:

There is an advantage to the C approach of separating out some
facilities and supplying them only in the standard library.

 It goes a bit further: for a general purpose language, any existing
functionality that cannot be written using the language is a sign of
a weakness because it shows that despite being "general purpose" it
fails to cover this specific "purpose".
 In an ideal world, it would be better if we could define `malloc` and
`memmove` efficiently in standard C, but at least they can be
implemented in non-standard C.
 

I don't see an advantage in being able to implement them in standard C. I /do/ see an advantage in being able to do so well in non-standard, implementation-specific C.
The reason why you might want your own special memmove, or your own special malloc, is that you are doing niche and specialised software. For example, you might be making real-time software and require specific time constraints on these functions.  In such cases, you are not interested in writing fully portable software - it will already contain many implementation-specific features or use compiler extensions.