need help with a c++ procedure

[Mark Polesky]

continued from:
http://lists.gnu.org/archive/html/lilypond-devel/2013-08/msg00436.html

Hi everyone,

I'm trying to make something like an `installed-font?'
scheme procedure, but it looks like I need a c++ procedure
first.  Something like `ly_font_config_get_fonts', exactly
like the following except it would return the list of fonts
instead of displaying it.  This is from
font-config-scheme.cc:


   LY_DEFINE (ly_font_config_display_fonts, "ly:font-config-display-fonts", 0, 
0, 0,
              (), 
              "Dump a list of all fonts visible to FontConfig.")
   {   
     string str = display_list (NULL);
     str += display_config (NULL);

     progress_indication (str);

     return SCM_UNSPECIFIED;
   }   


I know almost nothing about c++, so if anyone could help,
that would be awesome.

Thanks.
- Mark