Some results on running  'g++ -E | wc -l' with the appropriate
includes/defines and a single #include in a compilation unit:

boost/signal.hpp                 : 62141
boost/signals/trackable.hpp      : 40849
boost/tokenizer.hpp              : 39490
boost/iterator/indirect_iterator : 36922
boost/signals/connection.hpp     : 34957
boost/function.hpp               : 31379
boost/array.hpp                  : 30205
boost/utility.hpp                : 30063
boost/cregex.hpp                 : 21575
boost/shared_ptr.hpp             : 17469
boost/scoped_ptr.hpp             : 11411
boost/crc.hpp                    : 5851
boost/tuple/tuple.hpp            : 4927
boost/scoped_array.hpp           : 3029
boost/assert.hpp                 : 52
boost/current_function.hpp       : 21

string                           : 18781
vector                           : 11994
map                              : 12467
list                             : 11134
deque                            : 11805
iosfwd                           : 6462
iostream                         : 29529

QObject                          : 5601
QString                          : 3876
QList                            : 1931
QVector                          : 4165
QMap                             : 2831
QHash                            : 7098
QRegExp                          : 3959   (boost/cregex.hpp     : 21575 
QSharedData                      : 838    (boost/shared_ptr.hpp : 17469)

Revision 21692: non-monolithic
Total:         compiled: 17310566  real: 150056  ratio: 115
graphics:      compiled:   669162  real:   2617  ratio: 255
frontends/qt4: compiled:  4386626  real:  27020  ratio: 162
support:       compiled:  1432410  real:   9600  ratio: 149
mathed:        compiled:  2357984  real:  19339  ratio: 121
insets:        compiled:  2415915  real:  21566  ratio: 112
src/*.cpp:     compiled:  4318608  real:  54814  ratio:  78

Revision 24415: non-monolithic
frontends/qt4: compiled:  4296379  real:  34614  ratio: 124
insets:        compiled:  2535206  real:  22128  ratio: 114 

Revision 24415: monolithic
frontends/qt4: compiled:   209600  real: 34614   ratio:   6
insets:        compiled:   122255  real: 22128   ratio:   5