https://issues.dlang.org/show_bug.cgi?id=11810
--- Comment #8 from Nick Treleaven <[email protected]> --- Here's as far as I got: https://github.com/ntrel/phobos/commits/byLine-fast This is faster than standard byLine on my Windows box iff std.utf.validate is not called for each line. To be honest, I'm not sure whether std.stdio.readln is doing UTF validation or not. readln has different implementations so performance of standard byLine varies by platform. I'm not sure whether this would be accepted as a PR. One issue is that when using stdin you couldn't input just one line at a time anymore. --
