A Tour of Go Struct Literals

A struct literal denotes a newly allocated struct value by listing the values of its fields.

You can list just a subset of fields by using the Name: syntax. (And the order of named fields is irrelevant.)

The special prefix & constructs a pointer to a newly allocated struct.

package main 

import "fmt"

type Vertex struct {
    X, Y int
}

var (
    p = Vertex{, } // has type Vertex
    q = &Vertex{, } // has type *Vertex
    r = Vertex{X: } // Y:0 is implicit
    s = Vertex{} // X:0 and Y:0
)
func main() {
    fmt.Println(p, q, r, s)
}