From the article:
> it’s completely bonkers to expect the average user to build an overloaded callable object with recursive templates just to see if the thing they’re looking at holds an int or a string.
You don't have to: http://en.cppreference.com/w/cpp/utility/variant/holds_alter... (and http://en.cppreference.com/w/cpp/utility/variant/get to access the value).
Not the same as what the article is trying to accomplish, which is an exhaustive match (i.e., any unmatched value is guaranteed to fail at compile time).
For example, consider a parser that matches on tokens. If you add a new token, the match should fail, because you want to guarantee, at compile-time, that every possible case is handled.
This is one reason that the lack of sum types in Go is so painful, to the point that someone wrote a special library for it [1].