Hello!

I'm writing application which uses Mongo. But actually sometimes mongo could not run in time due to Linux init manager issues.

So I need some way to check connection to Mongodb. I deeply reviewed API documents about C++ 11 driver but could not find any way to check connection without real requests.

Could you add something like this?

Also function db.has_collection() haven't any way to tell about errors. And case "no connection to mongo" and "we haven't this database" handled in same way. That's not perfect