Pathological import symbol shadowing

[Mathias LANG]

On Friday, 13 November 2020 at 22:57:03 UTC, H. S. Teoh wrote:
>
> D's import implementation was supposed to be designed to 
> prevent symbol hijacking, but in this case it's falling flat on 
> its face.
>
> Why can't we make it so that symbols that aren't explicitly 
> named on the import line would add to existing overload sets 
> instead of replacing them?
>
>
> T

Wouldn't *that* allow hijacking? Unless of course you remove 
implicit conversions of parameters. If you have a `void 
foo(short)` in a module, and you're using it from your main like 
so: `foo(42);`, then suddenly, if overload sets were merged, 
another import at the same level could introduce `void foo(int)`, 
which would be a better match, and hijack the call, instead of 
creating an error as done currently.