func (v Uint64) Get(deflt uint64) uint64 {
	if !v.Defined {
		return deflt
	}
	return v.V
}
Get returns the value or given default in the case the value is undefined.
package opt
import (
	"fmt"
	"github.com/mailru/easyjson/jlexer"
	"github.com/mailru/easyjson/jwriter"
)
type Uint64 struct {
	V       uint64
	Defined bool
}
func OUint64(v uint64) Uint64 {
	return Uint64{V: v, Defined: true}
}