| package pflag | 
 |  | 
 | import ( | 
 | 	"fmt" | 
 | 	"net" | 
 | ) | 
 |  | 
 | // -- net.IPMask value | 
 | type ipMaskValue net.IPMask | 
 |  | 
 | func newIPMaskValue(val net.IPMask, p *net.IPMask) *ipMaskValue { | 
 | 	*p = val | 
 | 	return (*ipMaskValue)(p) | 
 | } | 
 |  | 
 | func (i *ipMaskValue) String() string { return net.IPMask(*i).String() } | 
 | func (i *ipMaskValue) Set(s string) error { | 
 | 	ip := ParseIPv4Mask(s) | 
 | 	if ip == nil { | 
 | 		return fmt.Errorf("failed to parse IP mask: %q", s) | 
 | 	} | 
 | 	*i = ipMaskValue(ip) | 
 | 	return nil | 
 | } | 
 | func (i *ipMaskValue) Get() interface{} { | 
 | 	return net.IPMask(*i) | 
 | } | 
 |  | 
 | // Parse IPv4 netmask written in IP form (e.g. 255.255.255.0). | 
 | // This function should really belong to the net package. | 
 | func ParseIPv4Mask(s string) net.IPMask { | 
 | 	mask := net.ParseIP(s) | 
 | 	if mask == nil { | 
 | 		return nil | 
 | 	} | 
 | 	return net.IPv4Mask(mask[12], mask[13], mask[14], mask[15]) | 
 | } | 
 |  | 
 | // IPMaskVar defines an net.IPMask flag with specified name, default value, and usage string. | 
 | // The argument p points to an net.IPMask variable in which to store the value of the flag. | 
 | func (f *FlagSet) IPMaskVar(p *net.IPMask, name string, value net.IPMask, usage string) { | 
 | 	f.VarP(newIPMaskValue(value, p), name, "", usage) | 
 | } | 
 |  | 
 | // Like IPMaskVar, but accepts a shorthand letter that can be used after a single dash. | 
 | func (f *FlagSet) IPMaskVarP(p *net.IPMask, name, shorthand string, value net.IPMask, usage string) { | 
 | 	f.VarP(newIPMaskValue(value, p), name, shorthand, usage) | 
 | } | 
 |  | 
 | // IPMaskVar defines an net.IPMask flag with specified name, default value, and usage string. | 
 | // The argument p points to an net.IPMask variable in which to store the value of the flag. | 
 | func IPMaskVar(p *net.IPMask, name string, value net.IPMask, usage string) { | 
 | 	commandLine.VarP(newIPMaskValue(value, p), name, "", usage) | 
 | } | 
 |  | 
 | // Like IPMaskVar, but accepts a shorthand letter that can be used after a single dash. | 
 | func IPMaskVarP(p *net.IPMask, name, shorthand string, value net.IPMask, usage string) { | 
 | 	commandLine.VarP(newIPMaskValue(value, p), name, shorthand, usage) | 
 | } | 
 |  | 
 | // IPMask defines an net.IPMask flag with specified name, default value, and usage string. | 
 | // The return value is the address of an net.IPMask variable that stores the value of the flag. | 
 | func (f *FlagSet) IPMask(name string, value net.IPMask, usage string) *net.IPMask { | 
 | 	p := new(net.IPMask) | 
 | 	f.IPMaskVarP(p, name, "", value, usage) | 
 | 	return p | 
 | } | 
 |  | 
 | // Like IPMask, but accepts a shorthand letter that can be used after a single dash. | 
 | func (f *FlagSet) IPMaskP(name, shorthand string, value net.IPMask, usage string) *net.IPMask { | 
 | 	p := new(net.IPMask) | 
 | 	f.IPMaskVarP(p, name, shorthand, value, usage) | 
 | 	return p | 
 | } | 
 |  | 
 | // IPMask defines an net.IPMask flag with specified name, default value, and usage string. | 
 | // The return value is the address of an net.IPMask variable that stores the value of the flag. | 
 | func IPMask(name string, value net.IPMask, usage string) *net.IPMask { | 
 | 	return commandLine.IPMaskP(name, "", value, usage) | 
 | } | 
 |  | 
 | // Like IP, but accepts a shorthand letter that can be used after a single dash. | 
 | func IPMaskP(name, shorthand string, value net.IPMask, usage string) *net.IPMask { | 
 | 	return commandLine.IPMaskP(name, shorthand, value, usage) | 
 | } |