D mentioned on Rust discussions site

[Walter Bright]

On 5/22/2020 12:08 AM, Araq wrote:
> [x] Users had to patch every function in order to get type safety. Check.

They didn't have to change anything. The following code compiles today on gcc:

     foo(i, j) { return i + j; }


> [x] Compiler writers had considerable effort in implementing the new standards. 
> Check.

Nope. (Note that I speak from actual experience.) Want something that's hard to 
implement? See exception handling, which wasn't added.

Ya know, I've actually implemented a K+R compiler, then upgraded it to C89, then 
C99. You've got a very tough hill to climb trying to tell me what is hard to 
implement and what isn't.


> [x] New features like overloading, and type system extension like 'const' or 
> 'restrict' were added. Check.

Overloading was not added. 'const' was added, but could be ignored, and did not 
result in any significant coding style change. I already discussed 'restrict' 
which remains unused.


> [x] New code doesn't compile with older compilers without jumping through all 
> sort of hoops. Check.

That's true of any new feature, trivial or not.