On Monday, 24 February 2020 at 22:11:08 UTC, Walter Bright wrote:
The semantics of an interpolated string must be defined by the DIP, not deferred to some template. If the implementation of those defined language features is done by a template, that is an implementation choice, not part of the DIP or spec.
I don't understand this. The behavior of formatting strings is *currently* deferred to a template (std.format and co). This lets us do important decisions at compiletime, like writing the format string to a file or a string buffer piecewise without allocating memory. Why are you trying to get rid of this flexibility?
As I understand it, the point of a format string template is to keep exactly this kind of flexibility in exactly the same places it is currently available to users, while simultaneously improving syntax legibility. To emphasize this again: the @gc format string would have *reduced* flexibility for 90% of our usecases (templated nogc/lowgc log library calls). As proposed, I don't see why I would have ever used it.
