Ch-5 Bronze challenge question

I figured out the Bronze challenge at the end of 5. Except for one thing.

let point = (x: 1, y: 4)

switch point {
case let q1 where (point.x > 0) && (point.y > 0):

How does q1 become the value of “point”

I get what is going on, i just don’t get the mechanic of q1 is = to point now.

Otherwise great book… enjoying it, and that is rare for reading a programming book.

This is value binding as seen on p.40. “Value binding allows you to bind the matching value in a certain case to a local constant to variable. The constant of variable is available to use only within the matching case’s body”

Also, the following if-statement does the same thing.

if point.x > 0 && point.y > 0 {
   let q1 = point
else if ... {
else {

You can always recast a switch statement as an if statement.