tokens: So , I 'm looking at GCC 5.4.0 ' s implementation , in /usr/include/c ++ /5/bits/range_access.h on my system , thinking I might write something similar , and I see :
ner_tags: O O O O O O B-Application B-Version O O O O O B-File_Name I-File_Name I-File_Name O O O O O O O O O O O O O O O