<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Jul 27, 2016, at 4:00 PM, Jacob Bandes-Storch <<a href="mailto:jtbandes@gmail.com" class="">jtbandes@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">I figured that sentence was in reference to the methods currently named flatten().<div class=""><br class=""></div><div class="">The proposal also said that the String-based version of joined(separator:) (which are implemented separately) should have a default separator of "". There is currently no flatten() for collections of Strings.</div><div class=""><br class=""></div><div class=""><a href="https://github.com/apple/swift/blob/c6e828f761fc30f7ce444431de7da52814f96595/stdlib/public/core/String.swift#L769" class="">https://github.com/apple/swift/blob/c6e828f761fc30f7ce444431de7da52814f96595/stdlib/public/core/String.swift#L769</a><br class=""></div><div class=""><br class=""></div><div class="">I doubt there would be a performance difference between adding `func joined() { return joined(separator: "") }` and changing the parameter to `separator: String = "”`.</div></div></div></blockquote></div><br class=""><div class="">I’ll let a stdlib guru comment on this :-)</div><div class=""><br class=""></div><div class="">-Chris</div></body></html>