Actually, I've been addressing the problem at its source. That is I've eliminated the header order requirement. Well almost. There is one unavoidable exception - export.hpp and a couple of cases where I missed it. I'm still working on those. Robert Ramey Merrill Cornish wrote:

Robert,

Thanks. THAT did it. It also explained to me why this had worked before then "suddenly" stopped working. In the intervening time, I had "optimized" my headers and #includes. Somewhere along the way, I got serialization headers before archive headers.

Would it be useful to put something like

#define BOOST_SERIALIZATION_HEADER_INCLUDED

in each serialization header file and

#ifdef BOOST_SERIALIZATION_HEADER_INCLUDED #error A Boost serialization header was included BEFORE an Boost archive header. #endif.

in each archive header file?

In the meantime, thanks for your help, thanks for the promptness of your help, and have warm, safe holidays.

Merrill