Right now we convert them to strings, but only if we aren't using an index.

> db.c.drop()
true
> db.c.insert(

{a:1}

)
ObjectId("4b85978ee567afca16af984e")
> db.c.find(

{a:/^1/}

)

{ "_id" : ObjectId("4b85978ee567afca16af984e"), "a" : 1 }

> db.c.ensureIndex(

{a:1}

)
> db.c.find(

{a:/^1/}

)
>