Preventing another 1028

[Walter Bright]

On 5/28/2020 2:56 AM, Timon Gehr wrote:
> [...]

There's a lot of imprecise language in the D spec, as I'm not very good at 
language lawyering, and much of it was written hastily. A couple years ago I 
started doing this section by section, but ran out of steam as my PRs were met 
with indifference and languished.

There's also the factor of experience showing weaknesses in the spec. Subsequent 
language changes often do not show up in the spec. The @safe stuff was written a 
seeming lifetime ago.

The precise language for @safe can certainly be improved, as has been done 
already for what a "@safe interface" is.