Using maps as sets by using structs in Go: Is the performance the reason?-CodePudding

I'm studying existing go-source-codes and notice the following approach too often:

intSet := map[int]struct{}{}
vals := []int{5, 10, 2, 5, 8, 7, 3, 9, 1, 2, 10}
for _, v := range vals {
    intSet[v] = struct{}{}
}
if _, ok := intSet[5]; ok {
    fmt.Println("5 is in the set")
}

After initial syntax-related difficulties, I understood the code but using structs as values does not seem logical to me; what do I miss?

Edit: Source code from the book Learning Go

CodePudding user response：

Because the struct{}{} cost zero storage usage which is called an empty struct. So it's very useful for only want to use the map as the set.