/usr/share/zsh/5.5.1/functions
Edit: /usr/share/zsh/5.5.1/functions/_expand_word (307B)
#compdef -K _expand_word complete-word \C-xe _list_expansions list-choices \C-xd
# Simple completion front-end implementing expansion.
local curcontext="$curcontext"
if [[ -z "$curcontext" ]]; then
curcontext="expand-word:::"
else
curcontext="expand-word:${curcontext#*:}"
fi
_main_complete _expand