> First I was going to suggest you to use mpl::front to retrieve the first element of the type sequence, but the new variant doc does not state that the first element of the type sequence will be created in the variant's memory. I remember to read that it was once the case.
 

At least, the document that appears at the site states so:
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http://www.boost.org/doc/libs/1_35_0/doc/html/variant/design.html#variant.design.never-empty