How to put default-directory into kill-ring?

[Marcin Borkowski]

Hi list,

quite often I want to put some full path to some file (usually
init.el).  It would be quite convenient for M-x pwd (or maybe C-u M-x
pwd?) to put its output into the kill ring, which is does not.  So: is
there any function to do this?  (I can easily write it myself, but
don't want to reinvent the wheel.)  If not, could this be considered a
feature request?

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Adam Mickiewicz University