[boost] [variant] 2 or more types requirement

From: Ronald Garcia (garcia_at_[hidden])
Date: 2003-02-21 16:33:41

Hi,

In reading through the variant docs, I noticed a requirement that at least
two types must be supported by the variant.  Is this meant for ease of
library implementation, or is this a means of protecting programmers from
themselves? :-)

It may not make sense for a human programmer to instantiate a variant
with one value in it, but I can picture situations where a code generator
might create a variant of only one type.  Handling this as a
special case can be tedious -- I have had related problems in the past
generating structs of zero elements in C. Even when a human programmer is
involved, one might prefer the clarity of a consistent implementation
style over the performance gain of special casing. These situations might
be worth considering.

Cheers,

ron