interpolation proposals and safety

[Steven Schveighoffer]

On Friday, 30 August 2024 at 15:21:49 UTC, Adam D Ruppe wrote:
> On Friday, 30 August 2024 at 14:36:56 UTC, Steven Schveighoffer 
> wrote:
>> Yes, I purposely said log, because that's the intention of 
>> `writeln`.
>
> Gonna disagree with this: writeln's intention is to write a 
> line to the stdout stream. It has no more semantic knowledge; 
> it is fundamentally a low level function with a wide variety of 
> high level uses.

`writeln` has a *default mechanism* for writing out data. What 
does this default mechanism do? It dumps the contents of a 
struct. This screams "logging".

If `writeln` only supported strings, or required opt-in to string 
conversion (i.e. erroring without explicit `toString` function), 
then it would be clearer. But I can't see any purpose for this 
default other than logging data when it's useful.

But technically, this job belongs to `format`, so `writeln` 
indeed is a mechanism to output formatted data to a stream. It's 
just that the combination of formatting data with the default 
format being "contents of object" is best suited to logging.

If one is worried about accidentally writing badly-formatted or 
accidentally revealing data, one shouldn't use `writeln`.

This reminds me of javascript when you get a field on the screen 
and the text is `[Object object]`

-Steve