HanoiTower              application example for references 
as.ref                  coercing to reference 
deref                   dereferencing references 
is.ref                  checking (for) references 
optimal.index           creating standardized, memory optimized index
                        for subsetting 
ref                     creating references 
refdata                 subsettable reference to matrix or data.frame 
regression.test.refdata
                        regression test for refdata 
sleep.wrapper           wrapper to get some measures for all platforms 
