D mentioned on Rust discussions site

[Araq]

On Thursday, 21 May 2020 at 20:34:19 UTC, Walter Bright wrote:

> A "quite different" change would be something like adding 
> modules, or getting rid of the preprocessor.

Or adding a memory model to the language for 
parallelism/concurrency so that you need to review every line of 
code in your optimizer and see if it does a transformation that 
is now invalid... Hmmm.