Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Contains the definition of regex_token_iterator, and STL-compatible iterator for tokenizing a string using a regular expression.

namespace boost {
  namespace xpressive {
    template<typename BidiIter> struct regex_token_iterator;
  }
}