[boost] variant questions

From: David Abrahams (dave_at_[hidden])
Date: 2003-08-29 14:56:04

1.
       "Each type specified as a bounded type must satisfy the
       BoundedType requirements. Note that variant itself satisfies
       BoundedType requirements with default construction. "

   a. What does the phrase "with default construction" mean above?

   b. Would it be possible to reduce the requirements a bit?  For
      example, it seems to me that if you don't need your variant to
      be assignable, you probably don't need assignability of the
      component elements.  This question is not motivated by any need
      on my part; I'm just askin'.

2.

       "All members of variant satisfy the strong guarantee of
       exception-safety."

    Seriously?  What if an underlying type's assignment operator gives
    only the basic guarantee?  Surely, if you in fact use the
    underlying type's assignment operator you can't give the strong
    guarantee?

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com