pointer

Documentation

Overview

Package pointer contains some util functions to operate go pointer.

Index

• func ExtractPointer(value any) any
• func IsNil(i interface{}) bool
• func Of[T any](v T) *T
• func UnwarpOr[T any](p *T, fallback T) T
• func UnwarpOrDefault[T any](p *T) T
• func Unwrap[T any](p *T) T
• func UnwrapOr[T any](p *T, fallback ...T) T

Examples

• ExtractPointer
• IsNil
• Of
• UnwarpOr
• UnwarpOrDefault
• Unwrap
• UnwrapOr

Functions

func ExtractPointer

func ExtractPointer(value any) any

ExtractPointer returns the underlying value by the given interface type Play: https://go.dev/play/p/D7HFjeWU2ZP

Example

a := 1
b := &a
c := &b
d := &c

result := ExtractPointer(d)

fmt.Println(result)

Output:

1

func IsNil

func IsNil(i interface{}) bool

IsNil returns true if the given interface is nil or the underlying value is nil.

Example

a := 1
b := &a
c := &b
d := &c
e := &d
var f *int

result1 := IsNil(a)
result2 := IsNil(b)
result3 := IsNil(c)
result4 := IsNil(d)
result5 := IsNil(e)
result6 := IsNil(f)
result7 := IsNil(nil)

fmt.Println(result1)
fmt.Println(result2)
fmt.Println(result3)
fmt.Println(result4)
fmt.Println(result5)
fmt.Println(result6)
fmt.Println(result7)

Output:

false
false
false
false
false
true
true

func Of

func Of[T any](v T) *T

Of returns a pointer to the value `v`. Play: https://go.dev/play/p/HFd70x4DrMj

Example

result1 := Of(123)
result2 := Of("abc")

fmt.Println(*result1)
fmt.Println(*result2)

Output:

123
abc

func UnwarpOr

func UnwarpOr[T any](p *T, fallback T) T

UnwarpOr returns the value from the pointer or fallback if the pointer is nil.

Play: https://go.dev/play/p/mmNaLC38W8C
Deprecated: Please use UnwrapOr

Example

a := 123
b := "abc"

var c *int
var d *string

result1 := UnwarpOr(&a, 456)
result2 := UnwarpOr(&b, "abc")
result3 := UnwarpOr(c, 456)
result4 := UnwarpOr(d, "def")

fmt.Println(result1)
fmt.Println(result2)
fmt.Println(result3)
fmt.Println(result4)

Output:

123
abc
456
def

func UnwarpOrDefault

func UnwarpOrDefault[T any](p *T) T

UnwarpOrDefault returns the value from the pointer or the default value if the pointer is nil.

Play: https://go.dev/play/p/ZnGIHf8_o4E
Deprecated: Please use UnwrapOr

Example

a := 123
b := "abc"

var c *int
var d *string

result1 := UnwarpOrDefault(&a)
result2 := UnwarpOrDefault(&b)
result3 := UnwarpOrDefault(c)
result4 := UnwarpOrDefault(d)

fmt.Println(result1)
fmt.Println(result2)
fmt.Println(result3)
fmt.Println(result4)

Output:

123
abc
0

func Unwrap

func Unwrap[T any](p *T) T

Unwrap returns the value from the pointer.

Play: https://go.dev/play/p/cgeu3g7cjWb
Deprecated: Please use UnwrapOr

Example

a := 123
b := "abc"

result1 := Unwrap(&a)
result2 := Unwrap(&b)

fmt.Println(result1)
fmt.Println(result2)

Output:

123
abc

func UnwrapOr

func UnwrapOr[T any](p *T, fallback ...T) T

UnwrapOr returns the value from the pointer or fallback if the pointer is nil.

Example

a := 123
b := "abc"

var c *int
var d *string

result1 := UnwrapOr(&a, 456)
result2 := UnwrapOr(&b, "efg")
result3 := UnwrapOr(c, 456)
result4 := UnwrapOr(d, "def")

fmt.Println(result1)
fmt.Println(result2)
fmt.Println(result3)
fmt.Println(result4)

Output:

123
abc
456
def