como-win32 toolset help needed

From: Beman Dawes (bdawes_at_[hidden])
Date: 2003-05-25 16:55:55

The Comeau compiler under Windows has an option (--a) which we need to 
compile most Boost tests correctly. It both increases compliance and adds 
certain warning messages.

OTOH, --a cannot be used to compiler certain Windows SDK headers such as 
winnt.h. There are a few Boost files which use these problem headers.

What is the best way to setup the como-win32 toolset to default to --a, but 
allow --a to be turned off for certain compiles?

Thanks,

--Beman

PS: I've been back and forth with Greg Comeau about --a, and he may someday 
get it to accept Windows headers with warnings rather than errors, but that 
isn't going to happen right away.