Why can't &3 work? Rob says 3 does not have a type and that's a problem. Would it be possible to change the Go compiler such that 3 has a type? (I'm guessing no, at least not easily, otherwise he'd be suggesting it, but I'm curious about the reason)
Why not? In fact it already kind-of does: Go has "default types" for most untyped constants. When you write
i := 3
> Numeric constants represent exact values of arbitrary precision and do not overflow.
package main
import (
"fmt"
)
const tst = 1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
func main() {
fmt.Println("%v", tst)
}
> An untyped constant has a default type which is the type to which the constant is implicitly converted in contexts where a typed value is required.
The default type for a number (integer) is int. If you were to add a period in that long string of zeros, the default for floating-point is float64.
tl;dr: Go uses casts to coerce values to the correct types, which means you couldn't get pointers to number literals for non-default number types.