With the inlib you can write histograms in a file at the AIDA XML format. The exlib permits to read this kind of file. As the reading needs the external package expat (a simple XML parser), the reading classes had been put in exlib.
You can have a writing example with :
cd <path to inlib> cd examples/cpp c++ -I../.. waxml.cpp ./a.out
The program produces the inlib_waxml.aida file. And you have a reading example for this file with :
cd <path to exlib> cd examples/cpp ./build raxml.cpp ./exlib_example_raxml ../../../inlib/examples/cpp/inlib_waxml.aida