> A program I'm writing requires that the Boost Regex library was
> compiled with ICU support.
> How can I determine at configure/compile time whether the Regex
> library has ICU support?
> I'd like to prevent the user from shooting him/herself in the foot.
Um, you can't detect it at compile time except that, if ICU is not in the
users include path then boost/regex/icu.hpp won't compile. You will also
get linker errors if you attempt to use ICU support and the library was
built without it. So.... an AC_TRY_LINK in your configure script along with
a minimal test program that invokes a u32regex would do the trick.