Re: Microsoft is considering moving to Rust; potential opportunity for Ada2020

[Brad Moore <bmoore.ada@gmail.com>]

On Tuesday, August 6, 2019 at 11:01:14 AM UTC-6, Alejandro R. Mosteo wrote:
> On 20/7/19 0:07, Simon Wright wrote:
> > Paul Rubin <no.email@nospam.invalid> writes:
> > 
> >> Optikos <optikos@verizon.net> writes:
> >>> Yes, I also was wondering why Microsoft isn't fervently exploring
> >>> adding a Rust-esque borrow checker to C#
> >>
> >> C# is garbage collected, I thought.  No need for anything like a
> >> borrow checker.
> > 
> > GC is about safely disposing of memory that's no longer accessible from
> > anywhere in the program.
> > 
> > Borrow checking (AIUI) is about making sure that only one part of the
> > program has write access to a particular piece of memory at once.
> 
> Yes and no. If you check the first chapters in the Rust tutorial, heap 
> memory reclamation is also performed deterministically when the borrow 
> checker determines some memory has no more references left pointing to it.
> 
> I've seen it described as static GC. I guess it's a side-effect of the 
> borrow checker; if you have to know how many mutable/immutable references 
> exist to a block of memory, you end knowing when none are left.
> 
> That's my superficial understanding (haven't done any serious Rust). I'm 
> frankly impressed by the concept. It seems to be a real contribution to 
> the general landscape. Too bad the syntax gets ugly pretty quickly; I 
> wonder about long-term maintainability.
> 
> Also, the particular interest of Microsoft in Rust is clear to me; it 
> precludes whole classes of memory errors that make for a big chunk of 
> security vulnerabilities.

I believe it is also not just related to concurrency. For example, if you pass a pointer to an object into a function which deletes the object, the compiler will detect that use of that pointer after calling the function is not allowed.

Brad