copyKit

Documentation

Index

• func Copy(dest, src interface{}) error
• func DeepCopy[T any](src T) (dest T, err error)

Functions

func Copy

func Copy(dest, src interface{}) error

Copy 浅拷贝

@param dest (1) 如果为nil，将返回error

(2) 必须是指针类型

@param src (1) 如果为nil，将返回error

(2) 指针类型 || 结构体实例

e.g.

b := &Bean{
	Id: 666,
}
src := map[string]interface{}{
	"b":   false,
	"tmp": b,
}
dest := make(map[string]interface{})
if err := copyKit.Copy(&dest, src); err != nil {
	panic(err)
}

// {"b":false,"tmp":{"Id":666}} <nil>
fmt.Println(jsonKit.MarshalToString(src, jsonKit.WithApi(jsoniter.ConfigCompatibleWithStandardLibrary)))
// {"b":false,"tmp":{"Id":666}} <nil>
fmt.Println(jsonKit.MarshalToString(dest, jsonKit.WithApi(jsoniter.ConfigCompatibleWithStandardLibrary)))

src["b"] = true
b.Id = 777

// {"b":true,"tmp":{"Id":777}} <nil>
fmt.Println(jsonKit.MarshalToString(src, jsonKit.WithApi(jsoniter.ConfigCompatibleWithStandardLibrary)))
// {"b":false,"tmp":{"Id":777}} <nil>
fmt.Println(jsonKit.MarshalToString(dest, jsonKit.WithApi(jsoniter.ConfigCompatibleWithStandardLibrary)))

func DeepCopy

func DeepCopy[T any](src T) (dest T, err error)

DeepCopy 深拷贝

PS: (1) unable to copy unexported fields in a struct (lowercase field names) (2) 不使用 github.com/mohae/deepcopy: 虽然效果一样，但不推荐使用（star少; 最后更新时间2017） (3) 不使用 github.com/jinzhu/copier: 深拷贝有bug，详见"Golang.wps"

@param src 可以为nil（此时将返回: nil, nil）

e.g. 传参为nil的情况

a, err := copyKit.DeepCopy[interface{}](nil)
if err != nil {
	panic(err)
}
fmt.Println(a)
fmt.Println(a == nil) // true

b, err := copyKit.DeepCopy[[]int](nil)
if err != nil {
	panic(err)
}
fmt.Println(b)
fmt.Println(b == nil) // true

c, err := copyKit.DeepCopy[map[string]interface{}](nil)
if err != nil {
	panic(err)
}
fmt.Println(c)
fmt.Println(c == nil) // true

e.g.1

b := &Bean{
	Id: 666,
}
src := map[string]interface{}{
	"b":   false,
	"tmp": b,
}
dest, err := copyKit.DeepCopy(src)
if err != nil {
	panic(err)
}

// {"b":false,"tmp":{"Id":666}} <nil>
fmt.Println(jsonKit.MarshalToString(src, jsonKit.WithApi(jsoniter.ConfigCompatibleWithStandardLibrary)))
// {"b":false,"tmp":{"Id":666}} <nil>
fmt.Println(jsonKit.MarshalToString(dest, jsonKit.WithApi(jsoniter.ConfigCompatibleWithStandardLibrary)))

src["b"] = true
b.Id = 777

// {"b":true,"tmp":{"Id":777}} <nil>
fmt.Println(jsonKit.MarshalToString(src, jsonKit.WithApi(jsoniter.ConfigCompatibleWithStandardLibrary)))
// {"b":false,"tmp":{"Id":666}} <nil>
fmt.Println(jsonKit.MarshalToString(dest, jsonKit.WithApi(jsoniter.ConfigCompatibleWithStandardLibrary)))