toString best practices

[Bastiaan Veelo]

On Thursday, 9 February 2023 at 17:49:58 UTC, Paolo Invernizzi 
wrote:
> ```
> import std.format, std.range.primitives;
>
> struct Point(T)
> {
>     T x, y;
>
>     void toString(W)(ref W writer, scope const ref 
> FormatSpec!char f) const
>     if (isOutputRange!(W, char))
>     {
>         put(writer, "(");
>         formatValue(writer, x, f);
>         put(writer, ", ");
>         formatValue(writer, y, f);
>         put(writer, ")");
>     }
> }
>
> void main(){
>
>         import std.format : format;
>         assert( format("%s", Point!int(1,2)) == "(1, 2)");
>
>     	import std.experimental.logger;
>     	sharedLog.infof("%s", Point!int(1,2));
> }
> ```

Pasting this into https://run.dlang.io/, it just works. That's 
for DMD 2.099, so it might be a regression -- or recent feature?

-- Bastiaan.