Hi,

I was surprised to find that the acc toolset in boost-build does not support 64 bit builds. I found an earlier posting about this, but it seems the original poster did not pursue the issue: http://lists.boost.org/boost-build/2007/02/16205.php

Anyway, basic 64 bit support was easily added with the following lines in acc.jam:
flags acc CFLAGS <address-model>64 : +DD64 ;
flags acc LINKFLAGS <address-model>64 : +DD64 ;

Thanks,
Jim Gallagher