[Issue 20663] writeln should be @nogc

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=20663

--- Comment #3 from Adam D. Ruppe <destructionator at gmail.com> ---
hmmm took a look at the code and the other thing that throws is on fwrite
errors. I forgot about those... could possibly throw a static instance or
something but that complicates the easy idea of just using replacement char.

--