C/C++ comments:

/* commented line */
normal line
start of line /* comment */ end of line
/* multi
   line 
   comment 
*/ after multi-line comment
// c++ comment
before c++ comment // c++ comment
/* c-comment
// with c++ comment
   in it */

/* should not see next line
#define foo bar
*/ foo should not be bar

Hash comments:

Normal line
# commented line
partly comment line, comment starts now: # this is a comment
# comment # comment #comment
not a comment
