Hands-On High Performance with Go

Set

A set is used to only store keys. Go doesn't have a set type, so a map of the type to a Boolean value is used frequently in order to build a set. The following code block is an implementation of an STL equivalent set:

package mainimport "fmt"func main() {    s := make(map[int]bool)    for i := 0; i < 5; i++ {        s[i] = true    }    delete(s, 4)    if s[2] {        fmt.Println("s[2] is set")    }    if !s[4] {        fmt.Println("s[4] was deleted")    }}

The resulting output shows that we were able to set and delete the values accordingly:

We can see from our output that our code can properly manipulate a set, which is crucial for common key–value pairings.