> Why don't you like visitor to dispatch the type stored in the variant?

I like it very much, and I use variant because of the power of the static visiting mechanism.
The reason I wanted to test if the variant contains its 1st type is the following: my variant is made of a list of shared-pointers to various types; there's a routine that initializes it with one of the types depending on some conditions, then it applies some visitor on the resulting variant and stores it then in a container - however, there's no "default" behavior, so if neither condition was met, the variant remains "uninitialized" - i.e. it contains 1st type "zero" ptr. I want neither apply the visitor on "empty" smartpointer nor store it in the container, so I have to know whether it was "really" created or not. Two simple ways I can think about are to test the resulting variant or to introduce some flag - of course, both ways are far from ideal...