Right now every library enabled and disables internal debug support individually. Its impossible to do it now from single place. Suggestion for guidelines: - If BOOST_NDEBUG is defined then all libraries will switch off any debug support (asserts, pre- and post-condition checking, invariants etc). There would be no exception. - If BOOST_DEBUG is defined then all available debug suport will be switched on. There would be no exceptions. - If neither of macros is defined then libraries will behave as they behave now - picking their own choice using library specific macros. This would allow fine grained customization. Enforcing this rule would require quite a lot of effort and cooperation though. For example all assert()s would need to convert to BOOST_ASSERT()s. /Pavel