Composite literal uses unkeyed fields

filter := bson.D{{"autorefid", "100"}}

But It is showing a warning saying:

primitive.E composite literal uses unkeyed fields

The warnings are creating a mess in my code.

The warnings can be stopped by setting the check flag to false.

$ go doc cmd/vet

By default all checks are performed. If any flags are explicitly set to true, only those tests are run. Conversely, if any flag is explicitly set to false, only those tests are disabled. Thus -printf=true runs the printf check, -printf=false runs all checks except the printf check.

Unkeyed composite literals

Flag: -composites

Composite struct literals that do not use the field-keyed syntax.

But the warning is due to not providing the keys name when setting the value in primitive.E struct.

Setting keys for primitive.E struct will remove the warning messages. For example

filter := bson.D{primitive.E{Key: "autorefid", Value: "100"}}

Package primitive contains types similar to Go primitives for BSON types can do not have direct Go primitive representations.

type E struct {
    Key   string
    Value interface{}

E represents a BSON element for a D. It is usually used inside a D.

For more information have a look at primitive.E