Re: [boost] [variant] Opinion on boost::safe_get<> and default boost::get<> behavior

Gottlob Frege wrote:

My gut feeling is that "does this variant contain a Z" should be a compile time error, because it obviously doesn't contain a Z. (Of course less obvious when variant is spelled 'T'.)

Or when it's spelled variant.

And because it *can* be a compile time error.

Well yes, that is why we are having this discussion.

In most C++ code, you need to go out of your way (eg dynamic_cast) to do type-stuff at runtime.

get<> ALWAYS does type-stuff at runtime. It's not going to get any less runtimey. It's just going to catch a few (not very common) errors. It's still a dynamic_cast; the equivalent of the strict get<> would be a dynamic_cast that tells you, at compile time, "this cast will always fail, don't do it." Which, in dynamic_cast's case, is - I suspect - going to be a mixed blessing unless it's a warning, not an error. That said, my recommendation still stands. Make get<> strict, see what happens.