template statistics

[Adam D. Ruppe]

On Wednesday, 3 June 2020 at 03:19:37 UTC, Walter Bright wrote:
> The thing is, `writeln("hello")` can be expanded to 
> `core.stdc.stdio.puts("hello")`. Done.

iff it is a string literal and only a string literal. tho the 
zero-terminator can be fixed with fwrite of course.

> Phobos seems to do a lot of "going around the Horn" instead of 
> taking the canal.

It actually tries to special-case string literals (and it does a 
fine job - the compile time on my computer is scarcely different 
than using `core.stdc.stdio`), but turns out this is trickier 
than it might seem since there's a lot of edge cases in real 
generic D code.

On Linux, this generic implementation costs about 0.04s in 
compile time. On Windows, it costs about 0.08s (which is probably 
more the cost of importing core.sys.windows.windows than anything 
else).

tbh I think this case looks worse than it is.