Feedback Thread: DIP 1036--String Interpolation Tuple Literals--Community Review Round 2

[Daniel N]

On Wednesday, 27 January 2021 at 10:33:53 UTC, Mike Parker wrote:
> This is the feedback thread for the second round of Community 
> Review of DIP 1036, "String Interpolation Tuple Literals".
>

There are many great qualities of DIP1036 and I hope it gets 
accepted, good luck!
But one area which I think could need improvement is:

1) The lowering (either that or I totally overlooked something 
obvious again).

writeln(i"I ate ${apples} apples and ${bananas} bananas totalling 
${apples + bananas} fruit.");

DIP1036 proposes the following rewrite:
writeln(interp!"I ate "(), apples, interp!" apples and "(), 
bananas, interp!" bananas totalling "(), apples + bananas, 
interp!" fruit."());

Wouldn't this lowering be both simpler and more more efficient?
writeln(interp!"I ate "(), apples, " apples and ", bananas, " 
bananas totalling ", apples + bananas, " fruit.");

Actually couldn't we go even futher?
immutable interp interp_tag; // an instance of some unique type 
with as low overhead as possible
writeln(interp_tag, "I ate ", apples, " apples and ", bananas, " 
bananas totalling ", apples + bananas, " fruit.");

This way you can overload with a normal function argument instead 
of using a template constraint and NO single template instance is 
created.

2) Also no fan of using abbreviated type-names(interp) in 
userfacing API:s