[gtkmm] Monospaced Unicode font?

["McGuinness, Brian B" <brian b mcguinness lmco com>]

The default font that comes up in a text window seems
to support the non-ASCII Unicode characters.  But it is
proportionaly-spaced.  I need to find a Unicode font that
is monospaced, e.g. for displaying program code.  Do you
know of any such fonts?  I am not sure how to examine the
fonts on my system and determine which are Unicode fonts.

Thanks very much.

--- Brian