The header file is available at https://code.google.com/p/re2/source/browse/re2/set.h https://code.google.com/p/re2/source/browse/re2/set.h , and if I recall co

The header file is available at https://code.google.com/p/re2/source/browse/re2/set.h https://code.google.com/p/re2/source/browse/re2/set.h , and if I recall correctly, it merges all the regexes into one DFA so that it's faster than just concatenating all your patterns into one string.