With the following exceptions WCSLIB 4.6 is thread-safe:
- The C code generated by Flex is not re-entrant. Flex does have the capacity for producing re-entrant scanners but they have a different API. This may be handled by a compile-time option in future but in the meantime calls to the header parsers should be serialized via a mutex.
- The low-level functions wcsnpv() and wcsnps() are not thread-safe but within the library itself they are only used by the Flex scanners wcspih() and wcsbth(). They would rarely need to be used by application programmers.
