Re: [boost] [variant] Warning: variadic templates in boost::variant

Steven Watanabe wrote:

The difference between tuple<> and variant<> is that tuple<> has exactly one possible value, but variant<> has no possible values.

Not conceptually. tuple<X,Y> is struct { X x; Y y; }. variant<X,Y> is union { X x; Y y; }. tuple<> is struct {}. variant<> is union {}. All are valid. It's not that important though. The current variant doesn't support this case, so there's not much reason for the variadic one to do so. Sorry for bringing it up.