func (p *parserMixin) OpenFile(flag int, perm os.FileMode) (target **os.File) {
	target = new(*os.File)
	p.OpenFileVar(target, flag, perm)
	return
}
File attempts to open a File with os.OpenFile(flag, perm).
package kingpin
import (
	"net"
	"net/url"
	"os"
	"time"
	"github.com/alecthomas/units"
)
type Settings interface {
	SetValue(value Value)
}
type parserMixin struct {
	value    Value
	required bool
}
func (p *parserMixin) SetValue(value Value) {
	p.value = value
}
func (p *parserMixin) String() (target *string) {
	target = new(string)
	p.StringVar(target)
	return
}
func (p *parserMixin) StringMap() (target *map[string]string) {
	target = &(map[string]string{})
	p.StringMapVar(target)
	return
}
func (p *parserMixin) Bool() (target *bool) {
	target = new(bool)
	p.BoolVar(target)
	return
}
func (p *parserMixin) Int() (target *int) {
	target = new(int)
	p.IntVar(target)
	return
}
func (p *parserMixin) Int64() (target *int64) {
	target = new(int64)
	p.Int64Var(target)
	return
}
func (p *parserMixin) Uint64() (target *uint64) {
	target = new(uint64)
	p.Uint64Var(target)
	return
}
func (p *parserMixin) Float() (target *float64) {
	target = new(float64)
	p.FloatVar(target)
	return
}
func (p *parserMixin) Duration() (target *time.Duration) {
	target = new(time.Duration)
	p.DurationVar(target)
	return
}
func (p *parserMixin) Bytes() (target *units.Base2Bytes) {
	target = new(units.Base2Bytes)
	p.BytesVar(target)
	return
}
func (p *parserMixin) IP() (target *net.IP) {
	target = new(net.IP)
	p.IPVar(target)
	return
}
func (p *parserMixin) TCP() (target **net.TCPAddr) {
	target = new(*net.TCPAddr)
	p.TCPVar(target)
	return
}
func (p *parserMixin) TCPVar(target **net.TCPAddr) {
	p.SetValue(newTCPAddrValue(target))
}
func (p *parserMixin) ExistingFile() (target *string) {
	target = new(string)
	p.ExistingFileVar(target)
	return
}
func (p *parserMixin) ExistingDir() (target *string) {
	target = new(string)
	p.ExistingDirVar(target)
	return
}
func (p *parserMixin) ExistingFileOrDir() (target *string) {
	target = new(string)
	p.ExistingFileOrDirVar(target)
	return
}
func (p *parserMixin) File() (target **os.File) {
	target = new(*os.File)
	p.FileVar(target)
	return
}