Boost C++ Libraries

The Boost.Regex library is thread safe when Boost is: you can verify that Boost is in thread safe mode by checking to see if BOOST_HAS_THREADS is defined: this macro is set automatically by the config system when threading support is turned on in your compiler.

Class basic_regex and its typedefs regex and wregex are thread safe, in that compiled regular expressions can safely be shared between threads. The matching algorithms regex_match, regex_search, and regex_replace are all re-entrant and thread safe. Class match_results is now thread safe, in that the results of a match can be safely copied from one thread to another (for example one thread may find matches and push match_results instances onto a queue, while another thread pops them off the other end), otherwise use a separate instance of match_results per thread.

The POSIX API functions are all re-entrant and thread safe, regular expressions compiled with regcomp can also be shared between threads.

Finally note that changing the global locale invalidates all compiled regular expressions, therefore calling set_locale from one thread while another uses regular expressions will produce unpredictable results.

There is also a requirement that there is only one thread executing prior to the start of main().