Link Error Using gcc49 port on Mac OS 10.9

[Geoffrey Odhner]

I just installed MacPorts, and gcc49, and tried to compile a simple 
program, which really should work, but I'm getting a link error.  I 
narrowed it down, and if I take out the use of any regex then it will 
link.  I can leave in the #include <regex> line, but if I have any line 
that actually does a regex_search or a regex_replace, then I get the 
following error output when I compile and link (with my compile line 
shown first):

g++-mp-4.9 -std=c++11 -ggdb test-program.cxx -o test-program
Undefined symbols for architecture x86_64:
   "__istype(int, unsigned long)", referenced from:
       std::ctype<char>::is(unsigned long, char) const in test-program.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status

Can anyone help me?  I don't know what to do next.

Regards,

Geoffrey Odhner