前往教学课程：这行的作用是什么？

I am doing the go tutorial and I had a question about this exercise... https://tour.golang.org/moretypes/5

I have only briefly worked with pointers and addresses in rudimentary C code before. My understanding is that the line p = &Vertex{1, 2} // has type *Vertex is pointing a new variable p to the address of Vertex.

Wouldn't this then be redefining the definition of the struct to set X, Y int = 1, 2

Here is the full code from the tutorial:

package main

import "fmt"

type Vertex struct {
    X, Y int
}

var (
    v1 = Vertex{1, 2}  // has type Vertex
    v2 = Vertex{X: 1}  // Y:0 is implicit
    v3 = Vertex{}      // X:0 and Y:0
    p  = &Vertex{1, 2} // has type *Vertex
)

func main() {
    fmt.Println(v1, p, v2, v3)
}

var p = &Vertex{1, 2} does the following:

• Creates an anonymous variable of type Vertex with the values 1 for x and 2 for y
• Creates a variable p of type *Vertex (pointer to Vertex)
• Sets p to point to the anonymous variable.

It doesn't affect the definition of the type.