Does 'ref' turn into a pointer during compile time?

[thebluepandabear via Digitalmars-d-learn]

Say you have the following function that takes in a `ref` 
parameter:

```D
void modify(ref int num) {
    num += 5;
}
```
Does the compiler turn that into the code below?

```D
void modify(int* num) {
    num += 5;
}
```

I was just wondering whether or not this is the case because I 
don't think this was touched in the book about D I am reading.