creates a directory ./spirit. Could you try moving this into a subdirectory boost, additionally. The final directory structure must be:
$SPIRIT21_ROOT/boost/spirit (/include/...)
And the -I $SPIRIT21_ROOT needs to be added to the compiler command line. All spirit headers are included as
#include <boost/spirit/include/...>
that means you need to tell the compiler the base directory the 'boost/spirit/...' is in.
Bingo: Just a question of getting everything in the right place. $ g++-4 -I spirit21_root -I $HOME/Desktop/boost_1_39_0 -o uint_parser uint_parser.cpp $ ./uint_parser initializing input strings... atoi: 1.42 [s] strtol: 1.36 [s] int_: 6.53 [s] Clearly I need a faster laptop! ;-) -ed ------------------------------------------------ "No more boom and bust." -- Dr. J. G. Brown, 1997