A little background, we've got Visual Studio 2008 C++/CLI library through which we'd like to expose a dictionary-mapped data abstraction. We'd like to be able to ask some questions about the dictionary mapping, whether for its keys, values, or some combination thereof.
Does boost offer something along these lines comparable to Linq?
If you mean sql-like syntax, then the answer is most likely no.
If you are up to creating your own Domain Specific Language, look at boost::spirit.
From a different perspective, in free associating brain jump, if you actually want to use database structures and an approximated inline query language you could try emweb's dbo:
http://www.webtoolkit.eu/wt/doc/tutorial/dbo/tutorial.html -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.