When Swift debuted, we said goodbye to using #pragma pre-processor definitions to organize our code. Don't worry, Xcode still has our backs. We can use a few different "special" comments in our code and Xcode will pick up on them and display them in its jump bar:

The extra dash character in the name of our MARK gets us those sweet separators in the source navigator dropdown.

Xcode also supports a similar bit of functionality for TODO and FIXME comments. They'll show up in bold in the same dropdown.

func launch() {
  // TODO: launch here
}

func land() {
  // FIXME: shouldn't crash
}

As a bonus, we can use a little regex magic to get Xcode to generate build warnings for TODO and FIXMEs. We'll just add a new Run Script build phase to our project that contains:

KEYWORDS="TODO|FIXME|\?\?\?:|\!\!\!:"
find "${SRCROOT}" \( -name "*.swift" \) -print0 | \
xargs -0 egrep --with-filename --line-number --only-matching "($KEYWORDS).*\$" | \
perl -p -e "s/($KEYWORDS)/ warning: \$1/"

Shout out to Jeffrey Sambells for originally sparking this idea!