[boost] [variant] Important changes re: boost::empty, etc.

From: Eric Friedman (ebf_at_[hidden])
Date: 2003-11-04 22:02:04

To all-

I've made several related changes to variant:

   1) changed the name of boost::empty to boost::blank;
   2) eliminated the variant<> syntax; and
   3) changed variant::empty() to always return false.

These changes were motivated chiefly by a desire on my part to avoid 
breaking interface changes in future Boost releases.

Specifically, in the next release "truly empty" variants may become 
possible. In such an event, it would seem important to distinguish such 
variants from variants with content of what is now called boost::blank.

Regardless, I find the new behavior clearer all around.

Eric