Simplification of @trusted

[Paul Backus]

On Thursday, 17 June 2021 at 20:42:20 UTC, Ola Fosheim Grøstad 
wrote:
> On Thursday, 17 June 2021 at 20:33:33 UTC, Paul Backus wrote:
>> Assuming [issue 20941][1] is fixed, yes.
>
> […]
>
>> Yes.
>
> Thanks.
>
> There seems to be many interpretations of what safe means 
> though. Right now, safe interfacing with C seems like opening 
> Pandora's box.
>
> Probably a good idea to write up a set of best practice rules 
> for making safe interfacing with C libraries (with examples).

A lot of people on the D forums have an incomplete or incorrect 
understanding of what memory safety means, and how D's @safe, 
@trusted and @system attributes can be used to help prove a 
program memory-safe. The interpretation that I and ag0aep6g have 
been describing is the correct one.

Re: interfacing with C, the best guarantee you can reasonably 
hope to achieve is "my @trusted code is memory safe as long as 
the C functions I'm calling behave as specified in the relevant 
documentation or standard." I go into more detail about this in 
[my blog post on memory safety in D][1].

[1]: 
https://pbackus.github.io/blog/what-does-memory-safety-really-mean-in-d.html