Compilation error

[Dekel Tsur]

g++ -DHAVE_CONFIG_H -I. -I. -I. -I.. -I.. -I../boost    -isystem
/usr/X11R6/include  -O -fno-rtti -fno-exceptions -W -Wall -c buffer.C
buffer.C:21: bitset: No such file or directory
make[2]: *** [buffer.o] Error 1