[gpderetta]

Boost.variant suffers for being correct by default (i.e. strongly exception safe) plus opt-in for speed, while the new std::variant can get in an invalid state if an exception is thrown at a bad time. Let's say that the trade-offs will be hotly debated until the standard actually ships.

[hellofunk]

The problem with Boost.variant is that all data is doubly allocated, including at least 1 heap allocation as a copy. This is not obvious and is certainly not what a lot of users would want. But you are right, it does this to avoid exceptional situations.

[Sharlin]

The tradeoffs have been hotly debated for years :) The current spec is finally something the committee could agree on, after countless proposals, counter-proposals, endless email discussions and long evenings at committee meetings.

[gpderetta]

I agree that the current spec is better than none at all, but it feels like a bad compromise. I would have preferred either a fully exception safe variant or one with an explicit empty state.