diff --git a/bool.go b/bool.go
new file mode 100644
index 0000000..4fd891a
--- /dev/null
+++ b/bool.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- bool Value
+type boolValue bool
+
+func newBoolValue(val bool, p *bool) *boolValue {
+	*p = val
+	return (*boolValue)(p)
+}
+
+func (b *boolValue) Set(s string) error {
+	v, err := strconv.ParseBool(s)
+	*b = boolValue(v)
+	return err
+}
+
+func (b *boolValue) String() string { return fmt.Sprintf("%v", *b) }
+
+// BoolVar defines a bool flag with specified name, default value, and usage string.
+// The argument p points to a bool variable in which to store the value of the flag.
+func (f *FlagSet) BoolVar(p *bool, name string, value bool, usage string) {
+	f.VarP(newBoolValue(value, p), name, "", usage)
+}
+
+// Like BoolVar, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) BoolVarP(p *bool, name, shorthand string, value bool, usage string) {
+	f.VarP(newBoolValue(value, p), name, shorthand, usage)
+}
+
+// BoolVar defines a bool flag with specified name, default value, and usage string.
+// The argument p points to a bool variable in which to store the value of the flag.
+func BoolVar(p *bool, name string, value bool, usage string) {
+	commandLine.VarP(newBoolValue(value, p), name, "", usage)
+}
+
+// Like BoolVar, but accepts a shorthand letter that can be used after a single dash.
+func BoolVarP(p *bool, name, shorthand string, value bool, usage string) {
+	commandLine.VarP(newBoolValue(value, p), name, shorthand, usage)
+}
+
+// Bool defines a bool flag with specified name, default value, and usage string.
+// The return value is the address of a bool variable that stores the value of the flag.
+func (f *FlagSet) Bool(name string, value bool, usage string) *bool {
+	p := new(bool)
+	f.BoolVarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Bool, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) BoolP(name, shorthand string, value bool, usage string) *bool {
+	p := new(bool)
+	f.BoolVarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Bool defines a bool flag with specified name, default value, and usage string.
+// The return value is the address of a bool variable that stores the value of the flag.
+func Bool(name string, value bool, usage string) *bool {
+	return commandLine.BoolP(name, "", value, usage)
+}
+
+// Like Bool, but accepts a shorthand letter that can be used after a single dash.
+func BoolP(name, shorthand string, value bool, usage string) *bool {
+	return commandLine.BoolP(name, shorthand, value, usage)
+}
diff --git a/duration.go b/duration.go
new file mode 100644
index 0000000..d885f7c
--- /dev/null
+++ b/duration.go
@@ -0,0 +1,74 @@
+package pflag
+
+import "time"
+
+// -- time.Duration Value
+type durationValue time.Duration
+
+func newDurationValue(val time.Duration, p *time.Duration) *durationValue {
+	*p = val
+	return (*durationValue)(p)
+}
+
+func (d *durationValue) Set(s string) error {
+	v, err := time.ParseDuration(s)
+	*d = durationValue(v)
+	return err
+}
+
+func (d *durationValue) String() string { return (*time.Duration)(d).String() }
+
+// Value is the interface to the dynamic value stored in a flag.
+// (The default value is represented as a string.)
+type Value interface {
+	String() string
+	Set(string) error
+}
+
+// DurationVar defines a time.Duration flag with specified name, default value, and usage string.
+// The argument p points to a time.Duration variable in which to store the value of the flag.
+func (f *FlagSet) DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
+	f.VarP(newDurationValue(value, p), name, "", usage)
+}
+
+// Like DurationVar, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) DurationVarP(p *time.Duration, name, shorthand string, value time.Duration, usage string) {
+	f.VarP(newDurationValue(value, p), name, shorthand, usage)
+}
+
+// DurationVar defines a time.Duration flag with specified name, default value, and usage string.
+// The argument p points to a time.Duration variable in which to store the value of the flag.
+func DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
+	commandLine.VarP(newDurationValue(value, p), name, "", usage)
+}
+
+// Like DurationVar, but accepts a shorthand letter that can be used after a single dash.
+func DurationVarP(p *time.Duration, name, shorthand string, value time.Duration, usage string) {
+	commandLine.VarP(newDurationValue(value, p), name, shorthand, usage)
+}
+
+// Duration defines a time.Duration flag with specified name, default value, and usage string.
+// The return value is the address of a time.Duration variable that stores the value of the flag.
+func (f *FlagSet) Duration(name string, value time.Duration, usage string) *time.Duration {
+	p := new(time.Duration)
+	f.DurationVarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Duration, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) DurationP(name, shorthand string, value time.Duration, usage string) *time.Duration {
+	p := new(time.Duration)
+	f.DurationVarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Duration defines a time.Duration flag with specified name, default value, and usage string.
+// The return value is the address of a time.Duration variable that stores the value of the flag.
+func Duration(name string, value time.Duration, usage string) *time.Duration {
+	return commandLine.DurationP(name, "", value, usage)
+}
+
+// Like Duration, but accepts a shorthand letter that can be used after a single dash.
+func DurationP(name, shorthand string, value time.Duration, usage string) *time.Duration {
+	return commandLine.DurationP(name, shorthand, value, usage)
+}
diff --git a/flag.go b/flag.go
index e828e48..b4b7b85 100644
--- a/flag.go
+++ b/flag.go
@@ -104,148 +104,12 @@
 	"io"
 	"os"
 	"sort"
-	"strconv"
 	"strings"
-	"time"
 )
 
 // ErrHelp is the error returned if the flag -help is invoked but no such flag is defined.
 var ErrHelp = errors.New("pflag: help requested")
 
-// -- bool Value
-type boolValue bool
-
-func newBoolValue(val bool, p *bool) *boolValue {
-	*p = val
-	return (*boolValue)(p)
-}
-
-func (b *boolValue) Set(s string) error {
-	v, err := strconv.ParseBool(s)
-	*b = boolValue(v)
-	return err
-}
-
-func (b *boolValue) String() string { return fmt.Sprintf("%v", *b) }
-
-// -- int Value
-type intValue int
-
-func newIntValue(val int, p *int) *intValue {
-	*p = val
-	return (*intValue)(p)
-}
-
-func (i *intValue) Set(s string) error {
-	v, err := strconv.ParseInt(s, 0, 64)
-	*i = intValue(v)
-	return err
-}
-
-func (i *intValue) String() string { return fmt.Sprintf("%v", *i) }
-
-// -- int64 Value
-type int64Value int64
-
-func newInt64Value(val int64, p *int64) *int64Value {
-	*p = val
-	return (*int64Value)(p)
-}
-
-func (i *int64Value) Set(s string) error {
-	v, err := strconv.ParseInt(s, 0, 64)
-	*i = int64Value(v)
-	return err
-}
-
-func (i *int64Value) String() string { return fmt.Sprintf("%v", *i) }
-
-// -- uint Value
-type uintValue uint
-
-func newUintValue(val uint, p *uint) *uintValue {
-	*p = val
-	return (*uintValue)(p)
-}
-
-func (i *uintValue) Set(s string) error {
-	v, err := strconv.ParseUint(s, 0, 64)
-	*i = uintValue(v)
-	return err
-}
-
-func (i *uintValue) String() string { return fmt.Sprintf("%v", *i) }
-
-// -- uint64 Value
-type uint64Value uint64
-
-func newUint64Value(val uint64, p *uint64) *uint64Value {
-	*p = val
-	return (*uint64Value)(p)
-}
-
-func (i *uint64Value) Set(s string) error {
-	v, err := strconv.ParseUint(s, 0, 64)
-	*i = uint64Value(v)
-	return err
-}
-
-func (i *uint64Value) String() string { return fmt.Sprintf("%v", *i) }
-
-// -- string Value
-type stringValue string
-
-func newStringValue(val string, p *string) *stringValue {
-	*p = val
-	return (*stringValue)(p)
-}
-
-func (s *stringValue) Set(val string) error {
-	*s = stringValue(val)
-	return nil
-}
-
-func (s *stringValue) String() string { return fmt.Sprintf("%s", *s) }
-
-// -- float64 Value
-type float64Value float64
-
-func newFloat64Value(val float64, p *float64) *float64Value {
-	*p = val
-	return (*float64Value)(p)
-}
-
-func (f *float64Value) Set(s string) error {
-	v, err := strconv.ParseFloat(s, 64)
-	*f = float64Value(v)
-	return err
-}
-
-func (f *float64Value) String() string { return fmt.Sprintf("%v", *f) }
-
-// -- time.Duration Value
-type durationValue time.Duration
-
-func newDurationValue(val time.Duration, p *time.Duration) *durationValue {
-	*p = val
-	return (*durationValue)(p)
-}
-
-func (d *durationValue) Set(s string) error {
-	v, err := time.ParseDuration(s)
-	*d = durationValue(v)
-	return err
-}
-
-func (d *durationValue) String() string { return (*time.Duration)(d).String() }
-
-// Value is the interface to the dynamic value stored in a flag.
-// (The default value is represented as a string.)
-type Value interface {
-	String() string
-	Set(string) error
-}
-
 // ErrorHandling defines how to handle flag parsing errors.
 type ErrorHandling int
 
@@ -446,390 +310,6 @@
 // Args returns the non-flag command-line arguments.
 func Args() []string { return commandLine.args }
 
-// BoolVar defines a bool flag with specified name, default value, and usage string.
-// The argument p points to a bool variable in which to store the value of the flag.
-func (f *FlagSet) BoolVar(p *bool, name string, value bool, usage string) {
-	f.VarP(newBoolValue(value, p), name, "", usage)
-}
-
-// Like BoolVar, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) BoolVarP(p *bool, name, shorthand string, value bool, usage string) {
-	f.VarP(newBoolValue(value, p), name, shorthand, usage)
-}
-
-// BoolVar defines a bool flag with specified name, default value, and usage string.
-// The argument p points to a bool variable in which to store the value of the flag.
-func BoolVar(p *bool, name string, value bool, usage string) {
-	commandLine.VarP(newBoolValue(value, p), name, "", usage)
-}
-
-// Like BoolVar, but accepts a shorthand letter that can be used after a single dash.
-func BoolVarP(p *bool, name, shorthand string, value bool, usage string) {
-	commandLine.VarP(newBoolValue(value, p), name, shorthand, usage)
-}
-
-// Bool defines a bool flag with specified name, default value, and usage string.
-// The return value is the address of a bool variable that stores the value of the flag.
-func (f *FlagSet) Bool(name string, value bool, usage string) *bool {
-	p := new(bool)
-	f.BoolVarP(p, name, "", value, usage)
-	return p
-}
-
-// Like Bool, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) BoolP(name, shorthand string, value bool, usage string) *bool {
-	p := new(bool)
-	f.BoolVarP(p, name, shorthand, value, usage)
-	return p
-}
-
-// Bool defines a bool flag with specified name, default value, and usage string.
-// The return value is the address of a bool variable that stores the value of the flag.
-func Bool(name string, value bool, usage string) *bool {
-	return commandLine.BoolP(name, "", value, usage)
-}
-
-// Like Bool, but accepts a shorthand letter that can be used after a single dash.
-func BoolP(name, shorthand string, value bool, usage string) *bool {
-	return commandLine.BoolP(name, shorthand, value, usage)
-}
-
-// IntVar defines an int flag with specified name, default value, and usage string.
-// The argument p points to an int variable in which to store the value of the flag.
-func (f *FlagSet) IntVar(p *int, name string, value int, usage string) {
-	f.VarP(newIntValue(value, p), name, "", usage)
-}
-
-// Like IntVar, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) IntVarP(p *int, name, shorthand string, value int, usage string) {
-	f.VarP(newIntValue(value, p), name, shorthand, usage)
-}
-
-// IntVar defines an int flag with specified name, default value, and usage string.
-// The argument p points to an int variable in which to store the value of the flag.
-func IntVar(p *int, name string, value int, usage string) {
-	commandLine.VarP(newIntValue(value, p), name, "", usage)
-}
-
-// Like IntVar, but accepts a shorthand letter that can be used after a single dash.
-func IntVarP(p *int, name, shorthand string, value int, usage string) {
-	commandLine.VarP(newIntValue(value, p), name, shorthand, usage)
-}
-
-// Int defines an int flag with specified name, default value, and usage string.
-// The return value is the address of an int variable that stores the value of the flag.
-func (f *FlagSet) Int(name string, value int, usage string) *int {
-	p := new(int)
-	f.IntVarP(p, name, "", value, usage)
-	return p
-}
-
-// Like Int, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) IntP(name, shorthand string, value int, usage string) *int {
-	p := new(int)
-	f.IntVarP(p, name, shorthand, value, usage)
-	return p
-}
-
-// Int defines an int flag with specified name, default value, and usage string.
-// The return value is the address of an int variable that stores the value of the flag.
-func Int(name string, value int, usage string) *int {
-	return commandLine.IntP(name, "", value, usage)
-}
-
-// Like Int, but accepts a shorthand letter that can be used after a single dash.
-func IntP(name, shorthand string, value int, usage string) *int {
-	return commandLine.IntP(name, shorthand, value, usage)
-}
-
-// Int64Var defines an int64 flag with specified name, default value, and usage string.
-// The argument p points to an int64 variable in which to store the value of the flag.
-func (f *FlagSet) Int64Var(p *int64, name string, value int64, usage string) {
-	f.VarP(newInt64Value(value, p), name, "", usage)
-}
-
-// Like Int64Var, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) Int64VarP(p *int64, name, shorthand string, value int64, usage string) {
-	f.VarP(newInt64Value(value, p), name, shorthand, usage)
-}
-
-// Int64Var defines an int64 flag with specified name, default value, and usage string.
-// The argument p points to an int64 variable in which to store the value of the flag.
-func Int64Var(p *int64, name string, value int64, usage string) {
-	commandLine.VarP(newInt64Value(value, p), name, "", usage)
-}
-
-// Like Int64Var, but accepts a shorthand letter that can be used after a single dash.
-func Int64VarP(p *int64, name, shorthand string, value int64, usage string) {
-	commandLine.VarP(newInt64Value(value, p), name, shorthand, usage)
-}
-
-// Int64 defines an int64 flag with specified name, default value, and usage string.
-// The return value is the address of an int64 variable that stores the value of the flag.
-func (f *FlagSet) Int64(name string, value int64, usage string) *int64 {
-	p := new(int64)
-	f.Int64VarP(p, name, "", value, usage)
-	return p
-}
-
-// Like Int64, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) Int64P(name, shorthand string, value int64, usage string) *int64 {
-	p := new(int64)
-	f.Int64VarP(p, name, shorthand, value, usage)
-	return p
-}
-
-// Int64 defines an int64 flag with specified name, default value, and usage string.
-// The return value is the address of an int64 variable that stores the value of the flag.
-func Int64(name string, value int64, usage string) *int64 {
-	return commandLine.Int64P(name, "", value, usage)
-}
-
-// Like Int64, but accepts a shorthand letter that can be used after a single dash.
-func Int64P(name, shorthand string, value int64, usage string) *int64 {
-	return commandLine.Int64P(name, shorthand, value, usage)
-}
-
-// UintVar defines a uint flag with specified name, default value, and usage string.
-// The argument p points to a uint variable in which to store the value of the flag.
-func (f *FlagSet) UintVar(p *uint, name string, value uint, usage string) {
-	f.VarP(newUintValue(value, p), name, "", usage)
-}
-
-// Like UintVar, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) UintVarP(p *uint, name, shorthand string, value uint, usage string) {
-	f.VarP(newUintValue(value, p), name, shorthand, usage)
-}
-
-// UintVar defines a uint flag with specified name, default value, and usage string.
-// The argument p points to a uint  variable in which to store the value of the flag.
-func UintVar(p *uint, name string, value uint, usage string) {
-	commandLine.VarP(newUintValue(value, p), name, "", usage)
-}
-
-// Like UintVar, but accepts a shorthand letter that can be used after a single dash.
-func UintVarP(p *uint, name, shorthand string, value uint, usage string) {
-	commandLine.VarP(newUintValue(value, p), name, shorthand, usage)
-}
-
-// Uint defines a uint flag with specified name, default value, and usage string.
-// The return value is the address of a uint  variable that stores the value of the flag.
-func (f *FlagSet) Uint(name string, value uint, usage string) *uint {
-	p := new(uint)
-	f.UintVarP(p, name, "", value, usage)
-	return p
-}
-
-// Like Uint, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) UintP(name, shorthand string, value uint, usage string) *uint {
-	p := new(uint)
-	f.UintVarP(p, name, shorthand, value, usage)
-	return p
-}
-
-// Uint defines a uint flag with specified name, default value, and usage string.
-// The return value is the address of a uint  variable that stores the value of the flag.
-func Uint(name string, value uint, usage string) *uint {
-	return commandLine.UintP(name, "", value, usage)
-}
-
-// Like Uint, but accepts a shorthand letter that can be used after a single dash.
-func UintP(name, shorthand string, value uint, usage string) *uint {
-	return commandLine.UintP(name, shorthand, value, usage)
-}
-
-// Uint64Var defines a uint64 flag with specified name, default value, and usage string.
-// The argument p points to a uint64 variable in which to store the value of the flag.
-func (f *FlagSet) Uint64Var(p *uint64, name string, value uint64, usage string) {
-	f.VarP(newUint64Value(value, p), name, "", usage)
-}
-
-// Like Uint64Var, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) Uint64VarP(p *uint64, name, shorthand string, value uint64, usage string) {
-	f.VarP(newUint64Value(value, p), name, shorthand, usage)
-}
-
-// Uint64Var defines a uint64 flag with specified name, default value, and usage string.
-// The argument p points to a uint64 variable in which to store the value of the flag.
-func Uint64Var(p *uint64, name string, value uint64, usage string) {
-	commandLine.VarP(newUint64Value(value, p), name, "", usage)
-}
-
-// Like Uint64Var, but accepts a shorthand letter that can be used after a single dash.
-func Uint64VarP(p *uint64, name, shorthand string, value uint64, usage string) {
-	commandLine.VarP(newUint64Value(value, p), name, shorthand, usage)
-}
-
-// Uint64 defines a uint64 flag with specified name, default value, and usage string.
-// The return value is the address of a uint64 variable that stores the value of the flag.
-func (f *FlagSet) Uint64(name string, value uint64, usage string) *uint64 {
-	p := new(uint64)
-	f.Uint64VarP(p, name, "", value, usage)
-	return p
-}
-
-// Like Uint64, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) Uint64P(name, shorthand string, value uint64, usage string) *uint64 {
-	p := new(uint64)
-	f.Uint64VarP(p, name, shorthand, value, usage)
-	return p
-}
-
-// Uint64 defines a uint64 flag with specified name, default value, and usage string.
-// The return value is the address of a uint64 variable that stores the value of the flag.
-func Uint64(name string, value uint64, usage string) *uint64 {
-	return commandLine.Uint64P(name, "", value, usage)
-}
-
-// Like Uint64, but accepts a shorthand letter that can be used after a single dash.
-func Uint64P(name, shorthand string, value uint64, usage string) *uint64 {
-	return commandLine.Uint64P(name, shorthand, value, usage)
-}
-
-// StringVar defines a string flag with specified name, default value, and usage string.
-// The argument p points to a string variable in which to store the value of the flag.
-func (f *FlagSet) StringVar(p *string, name string, value string, usage string) {
-	f.VarP(newStringValue(value, p), name, "", usage)
-}
-
-// Like StringVar, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) StringVarP(p *string, name, shorthand string, value string, usage string) {
-	f.VarP(newStringValue(value, p), name, shorthand, usage)
-}
-
-// StringVar defines a string flag with specified name, default value, and usage string.
-// The argument p points to a string variable in which to store the value of the flag.
-func StringVar(p *string, name string, value string, usage string) {
-	commandLine.VarP(newStringValue(value, p), name, "", usage)
-}
-
-// Like StringVar, but accepts a shorthand letter that can be used after a single dash.
-func StringVarP(p *string, name, shorthand string, value string, usage string) {
-	commandLine.VarP(newStringValue(value, p), name, shorthand, usage)
-}
-
-// String defines a string flag with specified name, default value, and usage string.
-// The return value is the address of a string variable that stores the value of the flag.
-func (f *FlagSet) String(name string, value string, usage string) *string {
-	p := new(string)
-	f.StringVarP(p, name, "", value, usage)
-	return p
-}
-
-// Like String, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) StringP(name, shorthand string, value string, usage string) *string {
-	p := new(string)
-	f.StringVarP(p, name, shorthand, value, usage)
-	return p
-}
-
-// String defines a string flag with specified name, default value, and usage string.
-// The return value is the address of a string variable that stores the value of the flag.
-func String(name string, value string, usage string) *string {
-	return commandLine.StringP(name, "", value, usage)
-}
-
-// Like String, but accepts a shorthand letter that can be used after a single dash.
-func StringP(name, shorthand string, value string, usage string) *string {
-	return commandLine.StringP(name, shorthand, value, usage)
-}
-
-// Float64Var defines a float64 flag with specified name, default value, and usage string.
-// The argument p points to a float64 variable in which to store the value of the flag.
-func (f *FlagSet) Float64Var(p *float64, name string, value float64, usage string) {
-	f.VarP(newFloat64Value(value, p), name, "", usage)
-}
-
-// Like Float64Var, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) Float64VarP(p *float64, name, shorthand string, value float64, usage string) {
-	f.VarP(newFloat64Value(value, p), name, shorthand, usage)
-}
-
-// Float64Var defines a float64 flag with specified name, default value, and usage string.
-// The argument p points to a float64 variable in which to store the value of the flag.
-func Float64Var(p *float64, name string, value float64, usage string) {
-	commandLine.VarP(newFloat64Value(value, p), name, "", usage)
-}
-
-// Like Float64Var, but accepts a shorthand letter that can be used after a single dash.
-func Float64VarP(p *float64, name, shorthand string, value float64, usage string) {
-	commandLine.VarP(newFloat64Value(value, p), name, shorthand, usage)
-}
-
-// Float64 defines a float64 flag with specified name, default value, and usage string.
-// The return value is the address of a float64 variable that stores the value of the flag.
-func (f *FlagSet) Float64(name string, value float64, usage string) *float64 {
-	p := new(float64)
-	f.Float64VarP(p, name, "", value, usage)
-	return p
-}
-
-// Like Float64, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) Float64P(name, shorthand string, value float64, usage string) *float64 {
-	p := new(float64)
-	f.Float64VarP(p, name, shorthand, value, usage)
-	return p
-}
-
-// Float64 defines a float64 flag with specified name, default value, and usage string.
-// The return value is the address of a float64 variable that stores the value of the flag.
-func Float64(name string, value float64, usage string) *float64 {
-	return commandLine.Float64P(name, "", value, usage)
-}
-
-// Like Float64, but accepts a shorthand letter that can be used after a single dash.
-func Float64P(name, shorthand string, value float64, usage string) *float64 {
-	return commandLine.Float64P(name, shorthand, value, usage)
-}
-
-// DurationVar defines a time.Duration flag with specified name, default value, and usage string.
-// The argument p points to a time.Duration variable in which to store the value of the flag.
-func (f *FlagSet) DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
-	f.VarP(newDurationValue(value, p), name, "", usage)
-}
-
-// Like DurationVar, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) DurationVarP(p *time.Duration, name, shorthand string, value time.Duration, usage string) {
-	f.VarP(newDurationValue(value, p), name, shorthand, usage)
-}
-
-// DurationVar defines a time.Duration flag with specified name, default value, and usage string.
-// The argument p points to a time.Duration variable in which to store the value of the flag.
-func DurationVar(p *time.Duration, name string, value time.Duration, usage string) {
-	commandLine.VarP(newDurationValue(value, p), name, "", usage)
-}
-
-// Like DurationVar, but accepts a shorthand letter that can be used after a single dash.
-func DurationVarP(p *time.Duration, name, shorthand string, value time.Duration, usage string) {
-	commandLine.VarP(newDurationValue(value, p), name, shorthand, usage)
-}
-
-// Duration defines a time.Duration flag with specified name, default value, and usage string.
-// The return value is the address of a time.Duration variable that stores the value of the flag.
-func (f *FlagSet) Duration(name string, value time.Duration, usage string) *time.Duration {
-	p := new(time.Duration)
-	f.DurationVarP(p, name, "", value, usage)
-	return p
-}
-
-// Like Duration, but accepts a shorthand letter that can be used after a single dash.
-func (f *FlagSet) DurationP(name, shorthand string, value time.Duration, usage string) *time.Duration {
-	p := new(time.Duration)
-	f.DurationVarP(p, name, shorthand, value, usage)
-	return p
-}
-
-// Duration defines a time.Duration flag with specified name, default value, and usage string.
-// The return value is the address of a time.Duration variable that stores the value of the flag.
-func Duration(name string, value time.Duration, usage string) *time.Duration {
-	return commandLine.DurationP(name, "", value, usage)
-}
-
-// Like Duration, but accepts a shorthand letter that can be used after a single dash.
-func DurationP(name, shorthand string, value time.Duration, usage string) *time.Duration {
-	return commandLine.DurationP(name, shorthand, value, usage)
-}
-
 // Var defines a flag with the specified name and usage string. The type and
 // value of the flag are represented by the first argument, of type Value, which
 // typically holds a user-defined implementation of Value. For instance, the
diff --git a/float32.go b/float32.go
new file mode 100644
index 0000000..7d37a10
--- /dev/null
+++ b/float32.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- float32 Value
+type float32Value float32
+
+func newFloat32Value(val float32, p *float32) *float32Value {
+	*p = val
+	return (*float32Value)(p)
+}
+
+func (f *float32Value) Set(s string) error {
+	v, err := strconv.ParseFloat(s, 32)
+	*f = float32Value(v)
+	return err
+}
+
+func (f *float32Value) String() string { return fmt.Sprintf("%v", *f) }
+
+// Float32Var defines a float32 flag with specified name, default value, and usage string.
+// The argument p points to a float32 variable in which to store the value of the flag.
+func (f *FlagSet) Float32Var(p *float32, name string, value float32, usage string) {
+	f.VarP(newFloat32Value(value, p), name, "", usage)
+}
+
+// Like Float32Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Float32VarP(p *float32, name, shorthand string, value float32, usage string) {
+	f.VarP(newFloat32Value(value, p), name, shorthand, usage)
+}
+
+// Float32Var defines a float32 flag with specified name, default value, and usage string.
+// The argument p points to a float32 variable in which to store the value of the flag.
+func Float32Var(p *float32, name string, value float32, usage string) {
+	commandLine.VarP(newFloat32Value(value, p), name, "", usage)
+}
+
+// Like Float32Var, but accepts a shorthand letter that can be used after a single dash.
+func Float32VarP(p *float32, name, shorthand string, value float32, usage string) {
+	commandLine.VarP(newFloat32Value(value, p), name, shorthand, usage)
+}
+
+// Float32 defines a float32 flag with specified name, default value, and usage string.
+// The return value is the address of a float32 variable that stores the value of the flag.
+func (f *FlagSet) Float32(name string, value float32, usage string) *float32 {
+	p := new(float32)
+	f.Float32VarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Float32, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Float32P(name, shorthand string, value float32, usage string) *float32 {
+	p := new(float32)
+	f.Float32VarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Float32 defines a float32 flag with specified name, default value, and usage string.
+// The return value is the address of a float32 variable that stores the value of the flag.
+func Float32(name string, value float32, usage string) *float32 {
+	return commandLine.Float32P(name, "", value, usage)
+}
+
+// Like Float32, but accepts a shorthand letter that can be used after a single dash.
+func Float32P(name, shorthand string, value float32, usage string) *float32 {
+	return commandLine.Float32P(name, shorthand, value, usage)
+}
diff --git a/float64.go b/float64.go
new file mode 100644
index 0000000..87ae59c
--- /dev/null
+++ b/float64.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- float64 Value
+type float64Value float64
+
+func newFloat64Value(val float64, p *float64) *float64Value {
+	*p = val
+	return (*float64Value)(p)
+}
+
+func (f *float64Value) Set(s string) error {
+	v, err := strconv.ParseFloat(s, 64)
+	*f = float64Value(v)
+	return err
+}
+
+func (f *float64Value) String() string { return fmt.Sprintf("%v", *f) }
+
+// Float64Var defines a float64 flag with specified name, default value, and usage string.
+// The argument p points to a float64 variable in which to store the value of the flag.
+func (f *FlagSet) Float64Var(p *float64, name string, value float64, usage string) {
+	f.VarP(newFloat64Value(value, p), name, "", usage)
+}
+
+// Like Float64Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Float64VarP(p *float64, name, shorthand string, value float64, usage string) {
+	f.VarP(newFloat64Value(value, p), name, shorthand, usage)
+}
+
+// Float64Var defines a float64 flag with specified name, default value, and usage string.
+// The argument p points to a float64 variable in which to store the value of the flag.
+func Float64Var(p *float64, name string, value float64, usage string) {
+	commandLine.VarP(newFloat64Value(value, p), name, "", usage)
+}
+
+// Like Float64Var, but accepts a shorthand letter that can be used after a single dash.
+func Float64VarP(p *float64, name, shorthand string, value float64, usage string) {
+	commandLine.VarP(newFloat64Value(value, p), name, shorthand, usage)
+}
+
+// Float64 defines a float64 flag with specified name, default value, and usage string.
+// The return value is the address of a float64 variable that stores the value of the flag.
+func (f *FlagSet) Float64(name string, value float64, usage string) *float64 {
+	p := new(float64)
+	f.Float64VarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Float64, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Float64P(name, shorthand string, value float64, usage string) *float64 {
+	p := new(float64)
+	f.Float64VarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Float64 defines a float64 flag with specified name, default value, and usage string.
+// The return value is the address of a float64 variable that stores the value of the flag.
+func Float64(name string, value float64, usage string) *float64 {
+	return commandLine.Float64P(name, "", value, usage)
+}
+
+// Like Float64, but accepts a shorthand letter that can be used after a single dash.
+func Float64P(name, shorthand string, value float64, usage string) *float64 {
+	return commandLine.Float64P(name, shorthand, value, usage)
+}
diff --git a/int.go b/int.go
new file mode 100644
index 0000000..fca1a25
--- /dev/null
+++ b/int.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- int Value
+type intValue int
+
+func newIntValue(val int, p *int) *intValue {
+	*p = val
+	return (*intValue)(p)
+}
+
+func (i *intValue) Set(s string) error {
+	v, err := strconv.ParseInt(s, 0, 64)
+	*i = intValue(v)
+	return err
+}
+
+func (i *intValue) String() string { return fmt.Sprintf("%v", *i) }
+
+// IntVar defines an int flag with specified name, default value, and usage string.
+// The argument p points to an int variable in which to store the value of the flag.
+func (f *FlagSet) IntVar(p *int, name string, value int, usage string) {
+	f.VarP(newIntValue(value, p), name, "", usage)
+}
+
+// Like IntVar, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) IntVarP(p *int, name, shorthand string, value int, usage string) {
+	f.VarP(newIntValue(value, p), name, shorthand, usage)
+}
+
+// IntVar defines an int flag with specified name, default value, and usage string.
+// The argument p points to an int variable in which to store the value of the flag.
+func IntVar(p *int, name string, value int, usage string) {
+	commandLine.VarP(newIntValue(value, p), name, "", usage)
+}
+
+// Like IntVar, but accepts a shorthand letter that can be used after a single dash.
+func IntVarP(p *int, name, shorthand string, value int, usage string) {
+	commandLine.VarP(newIntValue(value, p), name, shorthand, usage)
+}
+
+// Int defines an int flag with specified name, default value, and usage string.
+// The return value is the address of an int variable that stores the value of the flag.
+func (f *FlagSet) Int(name string, value int, usage string) *int {
+	p := new(int)
+	f.IntVarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Int, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) IntP(name, shorthand string, value int, usage string) *int {
+	p := new(int)
+	f.IntVarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Int defines an int flag with specified name, default value, and usage string.
+// The return value is the address of an int variable that stores the value of the flag.
+func Int(name string, value int, usage string) *int {
+	return commandLine.IntP(name, "", value, usage)
+}
+
+// Like Int, but accepts a shorthand letter that can be used after a single dash.
+func IntP(name, shorthand string, value int, usage string) *int {
+	return commandLine.IntP(name, shorthand, value, usage)
+}
diff --git a/int32.go b/int32.go
new file mode 100644
index 0000000..d41f315
--- /dev/null
+++ b/int32.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- int32 Value
+type int32Value int32
+
+func newInt32Value(val int32, p *int32) *int32Value {
+	*p = val
+	return (*int32Value)(p)
+}
+
+func (i *int32Value) Set(s string) error {
+	v, err := strconv.ParseInt(s, 0, 32)
+	*i = int32Value(v)
+	return err
+}
+
+func (i *int32Value) String() string { return fmt.Sprintf("%v", *i) }
+
+// Int32Var defines an int32 flag with specified name, default value, and usage string.
+// The argument p points to an int32 variable in which to store the value of the flag.
+func (f *FlagSet) Int32Var(p *int32, name string, value int32, usage string) {
+	f.VarP(newInt32Value(value, p), name, "", usage)
+}
+
+// Like Int32Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Int32VarP(p *int32, name, shorthand string, value int32, usage string) {
+	f.VarP(newInt32Value(value, p), name, shorthand, usage)
+}
+
+// Int32Var defines an int32 flag with specified name, default value, and usage string.
+// The argument p points to an int32 variable in which to store the value of the flag.
+func Int32Var(p *int32, name string, value int32, usage string) {
+	commandLine.VarP(newInt32Value(value, p), name, "", usage)
+}
+
+// Like Int32Var, but accepts a shorthand letter that can be used after a single dash.
+func Int32VarP(p *int32, name, shorthand string, value int32, usage string) {
+	commandLine.VarP(newInt32Value(value, p), name, shorthand, usage)
+}
+
+// Int32 defines an int32 flag with specified name, default value, and usage string.
+// The return value is the address of an int32 variable that stores the value of the flag.
+func (f *FlagSet) Int32(name string, value int32, usage string) *int32 {
+	p := new(int32)
+	f.Int32VarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Int32, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Int32P(name, shorthand string, value int32, usage string) *int32 {
+	p := new(int32)
+	f.Int32VarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Int32 defines an int32 flag with specified name, default value, and usage string.
+// The return value is the address of an int32 variable that stores the value of the flag.
+func Int32(name string, value int32, usage string) *int32 {
+	return commandLine.Int32P(name, "", value, usage)
+}
+
+// Like Int32, but accepts a shorthand letter that can be used after a single dash.
+func Int32P(name, shorthand string, value int32, usage string) *int32 {
+	return commandLine.Int32P(name, shorthand, value, usage)
+}
diff --git a/int64.go b/int64.go
new file mode 100644
index 0000000..adb4bdc
--- /dev/null
+++ b/int64.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- int64 Value
+type int64Value int64
+
+func newInt64Value(val int64, p *int64) *int64Value {
+	*p = val
+	return (*int64Value)(p)
+}
+
+func (i *int64Value) Set(s string) error {
+	v, err := strconv.ParseInt(s, 0, 64)
+	*i = int64Value(v)
+	return err
+}
+
+func (i *int64Value) String() string { return fmt.Sprintf("%v", *i) }
+
+// Int64Var defines an int64 flag with specified name, default value, and usage string.
+// The argument p points to an int64 variable in which to store the value of the flag.
+func (f *FlagSet) Int64Var(p *int64, name string, value int64, usage string) {
+	f.VarP(newInt64Value(value, p), name, "", usage)
+}
+
+// Like Int64Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Int64VarP(p *int64, name, shorthand string, value int64, usage string) {
+	f.VarP(newInt64Value(value, p), name, shorthand, usage)
+}
+
+// Int64Var defines an int64 flag with specified name, default value, and usage string.
+// The argument p points to an int64 variable in which to store the value of the flag.
+func Int64Var(p *int64, name string, value int64, usage string) {
+	commandLine.VarP(newInt64Value(value, p), name, "", usage)
+}
+
+// Like Int64Var, but accepts a shorthand letter that can be used after a single dash.
+func Int64VarP(p *int64, name, shorthand string, value int64, usage string) {
+	commandLine.VarP(newInt64Value(value, p), name, shorthand, usage)
+}
+
+// Int64 defines an int64 flag with specified name, default value, and usage string.
+// The return value is the address of an int64 variable that stores the value of the flag.
+func (f *FlagSet) Int64(name string, value int64, usage string) *int64 {
+	p := new(int64)
+	f.Int64VarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Int64, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Int64P(name, shorthand string, value int64, usage string) *int64 {
+	p := new(int64)
+	f.Int64VarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Int64 defines an int64 flag with specified name, default value, and usage string.
+// The return value is the address of an int64 variable that stores the value of the flag.
+func Int64(name string, value int64, usage string) *int64 {
+	return commandLine.Int64P(name, "", value, usage)
+}
+
+// Like Int64, but accepts a shorthand letter that can be used after a single dash.
+func Int64P(name, shorthand string, value int64, usage string) *int64 {
+	return commandLine.Int64P(name, shorthand, value, usage)
+}
diff --git a/int8.go b/int8.go
new file mode 100644
index 0000000..a169c1a
--- /dev/null
+++ b/int8.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- int8 Value
+type int8Value int8
+
+func newInt8Value(val int8, p *int8) *int8Value {
+	*p = val
+	return (*int8Value)(p)
+}
+
+func (i *int8Value) Set(s string) error {
+	v, err := strconv.ParseInt(s, 0, 8)
+	*i = int8Value(v)
+	return err
+}
+
+func (i *int8Value) String() string { return fmt.Sprintf("%v", *i) }
+
+// Int8Var defines an int8 flag with specified name, default value, and usage string.
+// The argument p points to an int8 variable in which to store the value of the flag.
+func (f *FlagSet) Int8Var(p *int8, name string, value int8, usage string) {
+	f.VarP(newInt8Value(value, p), name, "", usage)
+}
+
+// Like Int8Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Int8VarP(p *int8, name, shorthand string, value int8, usage string) {
+	f.VarP(newInt8Value(value, p), name, shorthand, usage)
+}
+
+// Int8Var defines an int8 flag with specified name, default value, and usage string.
+// The argument p points to an int8 variable in which to store the value of the flag.
+func Int8Var(p *int8, name string, value int8, usage string) {
+	commandLine.VarP(newInt8Value(value, p), name, "", usage)
+}
+
+// Like Int8Var, but accepts a shorthand letter that can be used after a single dash.
+func Int8VarP(p *int8, name, shorthand string, value int8, usage string) {
+	commandLine.VarP(newInt8Value(value, p), name, shorthand, usage)
+}
+
+// Int8 defines an int8 flag with specified name, default value, and usage string.
+// The return value is the address of an int8 variable that stores the value of the flag.
+func (f *FlagSet) Int8(name string, value int8, usage string) *int8 {
+	p := new(int8)
+	f.Int8VarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Int8, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Int8P(name, shorthand string, value int8, usage string) *int8 {
+	p := new(int8)
+	f.Int8VarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Int8 defines an int8 flag with specified name, default value, and usage string.
+// The return value is the address of an int8 variable that stores the value of the flag.
+func Int8(name string, value int8, usage string) *int8 {
+	return commandLine.Int8P(name, "", value, usage)
+}
+
+// Like Int8, but accepts a shorthand letter that can be used after a single dash.
+func Int8P(name, shorthand string, value int8, usage string) *int8 {
+	return commandLine.Int8P(name, shorthand, value, usage)
+}
diff --git a/ip.go b/ip.go
new file mode 100644
index 0000000..dccddc2
--- /dev/null
+++ b/ip.go
@@ -0,0 +1,75 @@
+package pflag
+
+import (
+	"fmt"
+	"net"
+)
+
+// -- net.IP value
+type ipValue net.IP
+
+func newIPValue(val net.IP, p *net.IP) *ipValue {
+	*p = val
+	return (*ipValue)(p)
+}
+
+func (i *ipValue) String() string { return net.IP(*i).String() }
+func (i *ipValue) Set(s string) error {
+	ip := net.ParseIP(s)
+	if ip == nil {
+		return fmt.Errorf("failed to parse IP: %q", s)
+	}
+	*i = ipValue(ip)
+	return nil
+}
+func (i *ipValue) Get() interface{} {
+	return net.IP(*i)
+}
+
+// IPVar defines an net.IP flag with specified name, default value, and usage string.
+// The argument p points to an net.IP variable in which to store the value of the flag.
+func (f *FlagSet) IPVar(p *net.IP, name string, value net.IP, usage string) {
+	f.VarP(newIPValue(value, p), name, "", usage)
+}
+
+// Like IPVar, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) IPVarP(p *net.IP, name, shorthand string, value net.IP, usage string) {
+	f.VarP(newIPValue(value, p), name, shorthand, usage)
+}
+
+// IPVar defines an net.IP flag with specified name, default value, and usage string.
+// The argument p points to an net.IP variable in which to store the value of the flag.
+func IPVar(p *net.IP, name string, value net.IP, usage string) {
+	commandLine.VarP(newIPValue(value, p), name, "", usage)
+}
+
+// Like IPVar, but accepts a shorthand letter that can be used after a single dash.
+func IPVarP(p *net.IP, name, shorthand string, value net.IP, usage string) {
+	commandLine.VarP(newIPValue(value, p), name, shorthand, usage)
+}
+
+// IP defines an net.IP flag with specified name, default value, and usage string.
+// The return value is the address of an net.IP variable that stores the value of the flag.
+func (f *FlagSet) IP(name string, value net.IP, usage string) *net.IP {
+	p := new(net.IP)
+	f.IPVarP(p, name, "", value, usage)
+	return p
+}
+
+// Like IP, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) IPP(name, shorthand string, value net.IP, usage string) *net.IP {
+	p := new(net.IP)
+	f.IPVarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// IP defines an net.IP flag with specified name, default value, and usage string.
+// The return value is the address of an net.IP variable that stores the value of the flag.
+func IP(name string, value net.IP, usage string) *net.IP {
+	return commandLine.IPP(name, "", value, usage)
+}
+
+// Like IP, but accepts a shorthand letter that can be used after a single dash.
+func IPP(name, shorthand string, value net.IP, usage string) *net.IP {
+	return commandLine.IPP(name, shorthand, value, usage)
+}
diff --git a/ipmask.go b/ipmask.go
new file mode 100644
index 0000000..35dc685
--- /dev/null
+++ b/ipmask.go
@@ -0,0 +1,85 @@
+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)
+}
diff --git a/string.go b/string.go
new file mode 100644
index 0000000..b1ae258
--- /dev/null
+++ b/string.go
@@ -0,0 +1,66 @@
+package pflag
+
+import "fmt"
+
+// -- string Value
+type stringValue string
+
+func newStringValue(val string, p *string) *stringValue {
+	*p = val
+	return (*stringValue)(p)
+}
+
+func (s *stringValue) Set(val string) error {
+	*s = stringValue(val)
+	return nil
+}
+
+func (s *stringValue) String() string { return fmt.Sprintf("%s", *s) }
+
+// StringVar defines a string flag with specified name, default value, and usage string.
+// The argument p points to a string variable in which to store the value of the flag.
+func (f *FlagSet) StringVar(p *string, name string, value string, usage string) {
+	f.VarP(newStringValue(value, p), name, "", usage)
+}
+
+// Like StringVar, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) StringVarP(p *string, name, shorthand string, value string, usage string) {
+	f.VarP(newStringValue(value, p), name, shorthand, usage)
+}
+
+// StringVar defines a string flag with specified name, default value, and usage string.
+// The argument p points to a string variable in which to store the value of the flag.
+func StringVar(p *string, name string, value string, usage string) {
+	commandLine.VarP(newStringValue(value, p), name, "", usage)
+}
+
+// Like StringVar, but accepts a shorthand letter that can be used after a single dash.
+func StringVarP(p *string, name, shorthand string, value string, usage string) {
+	commandLine.VarP(newStringValue(value, p), name, shorthand, usage)
+}
+
+// String defines a string flag with specified name, default value, and usage string.
+// The return value is the address of a string variable that stores the value of the flag.
+func (f *FlagSet) String(name string, value string, usage string) *string {
+	p := new(string)
+	f.StringVarP(p, name, "", value, usage)
+	return p
+}
+
+// Like String, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) StringP(name, shorthand string, value string, usage string) *string {
+	p := new(string)
+	f.StringVarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// String defines a string flag with specified name, default value, and usage string.
+// The return value is the address of a string variable that stores the value of the flag.
+func String(name string, value string, usage string) *string {
+	return commandLine.StringP(name, "", value, usage)
+}
+
+// Like String, but accepts a shorthand letter that can be used after a single dash.
+func StringP(name, shorthand string, value string, usage string) *string {
+	return commandLine.StringP(name, shorthand, value, usage)
+}
diff --git a/uint.go b/uint.go
new file mode 100644
index 0000000..cb0576d
--- /dev/null
+++ b/uint.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- uint Value
+type uintValue uint
+
+func newUintValue(val uint, p *uint) *uintValue {
+	*p = val
+	return (*uintValue)(p)
+}
+
+func (i *uintValue) Set(s string) error {
+	v, err := strconv.ParseUint(s, 0, 64)
+	*i = uintValue(v)
+	return err
+}
+
+func (i *uintValue) String() string { return fmt.Sprintf("%v", *i) }
+
+// UintVar defines a uint flag with specified name, default value, and usage string.
+// The argument p points to a uint variable in which to store the value of the flag.
+func (f *FlagSet) UintVar(p *uint, name string, value uint, usage string) {
+	f.VarP(newUintValue(value, p), name, "", usage)
+}
+
+// Like UintVar, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) UintVarP(p *uint, name, shorthand string, value uint, usage string) {
+	f.VarP(newUintValue(value, p), name, shorthand, usage)
+}
+
+// UintVar defines a uint flag with specified name, default value, and usage string.
+// The argument p points to a uint  variable in which to store the value of the flag.
+func UintVar(p *uint, name string, value uint, usage string) {
+	commandLine.VarP(newUintValue(value, p), name, "", usage)
+}
+
+// Like UintVar, but accepts a shorthand letter that can be used after a single dash.
+func UintVarP(p *uint, name, shorthand string, value uint, usage string) {
+	commandLine.VarP(newUintValue(value, p), name, shorthand, usage)
+}
+
+// Uint defines a uint flag with specified name, default value, and usage string.
+// The return value is the address of a uint  variable that stores the value of the flag.
+func (f *FlagSet) Uint(name string, value uint, usage string) *uint {
+	p := new(uint)
+	f.UintVarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Uint, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) UintP(name, shorthand string, value uint, usage string) *uint {
+	p := new(uint)
+	f.UintVarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Uint defines a uint flag with specified name, default value, and usage string.
+// The return value is the address of a uint  variable that stores the value of the flag.
+func Uint(name string, value uint, usage string) *uint {
+	return commandLine.UintP(name, "", value, usage)
+}
+
+// Like Uint, but accepts a shorthand letter that can be used after a single dash.
+func UintP(name, shorthand string, value uint, usage string) *uint {
+	return commandLine.UintP(name, shorthand, value, usage)
+}
diff --git a/uint16.go b/uint16.go
new file mode 100644
index 0000000..284fba1
--- /dev/null
+++ b/uint16.go
@@ -0,0 +1,71 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- uint16 value
+type uint16Value uint16
+
+func newUint16Value(val uint16, p *uint16) *uint16Value {
+	*p = val
+	return (*uint16Value)(p)
+}
+func (i *uint16Value) String() string { return fmt.Sprintf("%d", *i) }
+func (i *uint16Value) Set(s string) error {
+	v, err := strconv.ParseUint(s, 0, 16)
+	*i = uint16Value(v)
+	return err
+}
+func (i *uint16Value) Get() interface{} {
+	return uint16(*i)
+}
+
+// Uint16Var defines a uint flag with specified name, default value, and usage string.
+// The argument p points to a uint variable in which to store the value of the flag.
+func (f *FlagSet) Uint16Var(p *uint16, name string, value uint16, usage string) {
+	f.VarP(newUint16Value(value, p), name, "", usage)
+}
+
+// Like Uint16Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Uint16VarP(p *uint16, name, shorthand string, value uint16, usage string) {
+	f.VarP(newUint16Value(value, p), name, shorthand, usage)
+}
+
+// Uint16Var defines a uint flag with specified name, default value, and usage string.
+// The argument p points to a uint  variable in which to store the value of the flag.
+func Uint16Var(p *uint16, name string, value uint16, usage string) {
+	commandLine.VarP(newUint16Value(value, p), name, "", usage)
+}
+
+// Like Uint16Var, but accepts a shorthand letter that can be used after a single dash.
+func Uint16VarP(p *uint16, name, shorthand string, value uint16, usage string) {
+	commandLine.VarP(newUint16Value(value, p), name, shorthand, usage)
+}
+
+// Uint16 defines a uint flag with specified name, default value, and usage string.
+// The return value is the address of a uint  variable that stores the value of the flag.
+func (f *FlagSet) Uint16(name string, value uint16, usage string) *uint16 {
+	p := new(uint16)
+	f.Uint16VarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Uint16, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Uint16P(name, shorthand string, value uint16, usage string) *uint16 {
+	p := new(uint16)
+	f.Uint16VarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Uint16 defines a uint flag with specified name, default value, and usage string.
+// The return value is the address of a uint  variable that stores the value of the flag.
+func Uint16(name string, value uint16, usage string) *uint16 {
+	return commandLine.Uint16P(name, "", value, usage)
+}
+
+// Like Uint16, but accepts a shorthand letter that can be used after a single dash.
+func Uint16P(name, shorthand string, value uint16, usage string) *uint16 {
+	return commandLine.Uint16P(name, shorthand, value, usage)
+}
diff --git a/uint32.go b/uint32.go
new file mode 100644
index 0000000..25b646b
--- /dev/null
+++ b/uint32.go
@@ -0,0 +1,71 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- uint16 value
+type uint32Value uint32
+
+func newUint32Value(val uint32, p *uint32) *uint32Value {
+	*p = val
+	return (*uint32Value)(p)
+}
+func (i *uint32Value) String() string { return fmt.Sprintf("%d", *i) }
+func (i *uint32Value) Set(s string) error {
+	v, err := strconv.ParseUint(s, 0, 32)
+	*i = uint32Value(v)
+	return err
+}
+func (i *uint32Value) Get() interface{} {
+	return uint32(*i)
+}
+
+// Uint32Var defines a uint32 flag with specified name, default value, and usage string.
+// The argument p points to a uint32 variable in which to store the value of the flag.
+func (f *FlagSet) Uint32Var(p *uint32, name string, value uint32, usage string) {
+	f.VarP(newUint32Value(value, p), name, "", usage)
+}
+
+// Like Uint32Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Uint32VarP(p *uint32, name, shorthand string, value uint32, usage string) {
+	f.VarP(newUint32Value(value, p), name, shorthand, usage)
+}
+
+// Uint32Var defines a uint32 flag with specified name, default value, and usage string.
+// The argument p points to a uint32  variable in which to store the value of the flag.
+func Uint32Var(p *uint32, name string, value uint32, usage string) {
+	commandLine.VarP(newUint32Value(value, p), name, "", usage)
+}
+
+// Like Uint32Var, but accepts a shorthand letter that can be used after a single dash.
+func Uint32VarP(p *uint32, name, shorthand string, value uint32, usage string) {
+	commandLine.VarP(newUint32Value(value, p), name, shorthand, usage)
+}
+
+// Uint32 defines a uint32 flag with specified name, default value, and usage string.
+// The return value is the address of a uint32  variable that stores the value of the flag.
+func (f *FlagSet) Uint32(name string, value uint32, usage string) *uint32 {
+	p := new(uint32)
+	f.Uint32VarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Uint32, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Uint32P(name, shorthand string, value uint32, usage string) *uint32 {
+	p := new(uint32)
+	f.Uint32VarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Uint32 defines a uint32 flag with specified name, default value, and usage string.
+// The return value is the address of a uint32  variable that stores the value of the flag.
+func Uint32(name string, value uint32, usage string) *uint32 {
+	return commandLine.Uint32P(name, "", value, usage)
+}
+
+// Like Uint32, but accepts a shorthand letter that can be used after a single dash.
+func Uint32P(name, shorthand string, value uint32, usage string) *uint32 {
+	return commandLine.Uint32P(name, shorthand, value, usage)
+}
diff --git a/uint64.go b/uint64.go
new file mode 100644
index 0000000..4d892a7
--- /dev/null
+++ b/uint64.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- uint64 Value
+type uint64Value uint64
+
+func newUint64Value(val uint64, p *uint64) *uint64Value {
+	*p = val
+	return (*uint64Value)(p)
+}
+
+func (i *uint64Value) Set(s string) error {
+	v, err := strconv.ParseUint(s, 0, 64)
+	*i = uint64Value(v)
+	return err
+}
+
+func (i *uint64Value) String() string { return fmt.Sprintf("%v", *i) }
+
+// Uint64Var defines a uint64 flag with specified name, default value, and usage string.
+// The argument p points to a uint64 variable in which to store the value of the flag.
+func (f *FlagSet) Uint64Var(p *uint64, name string, value uint64, usage string) {
+	f.VarP(newUint64Value(value, p), name, "", usage)
+}
+
+// Like Uint64Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Uint64VarP(p *uint64, name, shorthand string, value uint64, usage string) {
+	f.VarP(newUint64Value(value, p), name, shorthand, usage)
+}
+
+// Uint64Var defines a uint64 flag with specified name, default value, and usage string.
+// The argument p points to a uint64 variable in which to store the value of the flag.
+func Uint64Var(p *uint64, name string, value uint64, usage string) {
+	commandLine.VarP(newUint64Value(value, p), name, "", usage)
+}
+
+// Like Uint64Var, but accepts a shorthand letter that can be used after a single dash.
+func Uint64VarP(p *uint64, name, shorthand string, value uint64, usage string) {
+	commandLine.VarP(newUint64Value(value, p), name, shorthand, usage)
+}
+
+// Uint64 defines a uint64 flag with specified name, default value, and usage string.
+// The return value is the address of a uint64 variable that stores the value of the flag.
+func (f *FlagSet) Uint64(name string, value uint64, usage string) *uint64 {
+	p := new(uint64)
+	f.Uint64VarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Uint64, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Uint64P(name, shorthand string, value uint64, usage string) *uint64 {
+	p := new(uint64)
+	f.Uint64VarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Uint64 defines a uint64 flag with specified name, default value, and usage string.
+// The return value is the address of a uint64 variable that stores the value of the flag.
+func Uint64(name string, value uint64, usage string) *uint64 {
+	return commandLine.Uint64P(name, "", value, usage)
+}
+
+// Like Uint64, but accepts a shorthand letter that can be used after a single dash.
+func Uint64P(name, shorthand string, value uint64, usage string) *uint64 {
+	return commandLine.Uint64P(name, shorthand, value, usage)
+}
diff --git a/uint8.go b/uint8.go
new file mode 100644
index 0000000..44cab5d
--- /dev/null
+++ b/uint8.go
@@ -0,0 +1,70 @@
+package pflag
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// -- uint8 Value
+type uint8Value uint8
+
+func newUint8Value(val uint8, p *uint8) *uint8Value {
+	*p = val
+	return (*uint8Value)(p)
+}
+
+func (i *uint8Value) Set(s string) error {
+	v, err := strconv.ParseUint(s, 0, 8)
+	*i = uint8Value(v)
+	return err
+}
+
+func (i *uint8Value) String() string { return fmt.Sprintf("%v", *i) }
+
+// Uint8Var defines a uint8 flag with specified name, default value, and usage string.
+// The argument p points to a uint8 variable in which to store the value of the flag.
+func (f *FlagSet) Uint8Var(p *uint8, name string, value uint8, usage string) {
+	f.VarP(newUint8Value(value, p), name, "", usage)
+}
+
+// Like Uint8Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Uint8VarP(p *uint8, name, shorthand string, value uint8, usage string) {
+	f.VarP(newUint8Value(value, p), name, shorthand, usage)
+}
+
+// Uint8Var defines a uint8 flag with specified name, default value, and usage string.
+// The argument p points to a uint8 variable in which to store the value of the flag.
+func Uint8Var(p *uint8, name string, value uint8, usage string) {
+	commandLine.VarP(newUint8Value(value, p), name, "", usage)
+}
+
+// Like Uint8Var, but accepts a shorthand letter that can be used after a single dash.
+func Uint8VarP(p *uint8, name, shorthand string, value uint8, usage string) {
+	commandLine.VarP(newUint8Value(value, p), name, shorthand, usage)
+}
+
+// Uint8 defines a uint8 flag with specified name, default value, and usage string.
+// The return value is the address of a uint8 variable that stores the value of the flag.
+func (f *FlagSet) Uint8(name string, value uint8, usage string) *uint8 {
+	p := new(uint8)
+	f.Uint8VarP(p, name, "", value, usage)
+	return p
+}
+
+// Like Uint8, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) Uint8P(name, shorthand string, value uint8, usage string) *uint8 {
+	p := new(uint8)
+	f.Uint8VarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// Uint8 defines a uint8 flag with specified name, default value, and usage string.
+// The return value is the address of a uint8 variable that stores the value of the flag.
+func Uint8(name string, value uint8, usage string) *uint8 {
+	return commandLine.Uint8P(name, "", value, usage)
+}
+
+// Like Uint8, but accepts a shorthand letter that can be used after a single dash.
+func Uint8P(name, shorthand string, value uint8, usage string) *uint8 {
+	return commandLine.Uint8P(name, shorthand, value, usage)
+}