To compile the 

libs/tuple/test/*.cpp 

files, you need to set include paths
for boost.
For example, in libs/tuple/test directory you would type (using g++):

g++ -I../../.. tuple_test_bench.cpp

The following is not true anymore:

  If you want to use tuple_io, you need to compile and link src/tuple.cpp:
  g++ -I../../.. ../src/tuple.cpp io_test.cpp

Thanks to Hartmut Kaiser's suggestion, the tuple.cpp is not needed anymore.
