Check object existence in mongo using gopkg.in/mgo.v2

I am looking for convinient way to check if object already exists in collection. For now the only way that i have found is

type result interface{}
var res result
err := col.Find(bson.M{"title": "title1"}).One(&res)
if err != nil {
	if err.Error() == "not found" {
		log.Println("No such document")
	} else {
		log.Println("err occured", err)
	}
}

I dont want to create variable res, in case if object exists, it can be very heavy document with a lot of fields.
I wish there would be another way, some Check() function which will just return bool value..
Basically I only need to know that object already stored in collection, I dont need itself

you have to use $exists

Syntax: { field: { $exists: <boolean> } }

For more details

http://docs.mongodb.org/manual/reference/operator/query/exists/

in the Official Mongo Driver you can get count of documents with specific key using CountDocuments function :

count, err := collection.CountDocuments(context.TODO(), bson.D{{"key", "value"}})