Does Passing 'this' by Value Impact Performance in Go Methods?

Does Passing "this" by Value Degrade Performance in Go Methods?

Unlike C where value-passed function arguments can result in significant performance penalties due to variable copying, Go's method receivers follow a different paradigm.

In Go, method receivers are mere syntactic conveniences. As demonstrated below:

type Something struct {
    Value int
}

func (s *Something) ChangeValue(n int) {
    s.Value = n
}

func main() {
    o := new(Something)
    fmt.Println(o.Value)           // Prints 0
    o.ChangeValue(8)             // Changes o's value to 8
    fmt.Println(o.Value)           // Prints 8
    (*Something).ChangeValue(o, 16) // Same as calling o.ChangeValue(16)
    fmt.Println(o.Value)           // Prints 16
}

Notice that the receiver s in ChangeValue is a pointer, making it similar to a reference in C . If the receiver were a value type, it wouldn't allow value mutation.

Therefore, Go's pointer receiver approach ensures encapsulation and prevents copying of the entire "this" instance, unlike the performance penalty observed in C/C for passing arguments by value.

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