Here is a nice trick to write an enum-like type's constant values:

g% cat x.go
package p

type T int

const (
    _ T = iota
    T1
    T2
    T3
    T4
)
g% 

This has two properties I wanted: (1) the values start at 1, so the zero value is not a
defined value, and (2) all the defined values have the same form on the line, so that I
can pipe them through 'sort' without breaking anything. Compare to

const (
    X T = 1 + iota
    Y
    Z
)

Anyway, this _ trick works well for me.

It works less well for godoc:

g% godoc .
PACKAGE DOCUMENTATION

package p
    import "."


CONSTANTS

const (
    T1
    T2
    T3
    T4
)

TYPES

type T int


g% 

It's a bit confusing that you can't see the _ in the godoc output, since the _ is what
defines the type and value of the constants.

Worse, the constants are not attached to the type T like they normally would be:

g% godoc . T
type T int


g% 

If I rename the _ to Dummy, then it works:

g% godoc . T
type T int

const (
    Dummy T = iota
    T1
    T2
    T3
    T4
)


g% 

What's happening here is that _ is treated as unexported and so it filters away.
(Renaming to dummy shows the same behavior as _.)

Perhaps the best fix would be to treat _ as exported for the purposes of godoc filtering
in const lists and possibly also struct fields (where _ is often padding).

I thought about saying that _ should be treated as exported for all filtering, but you
probably don't want to show things like

func _() { ... }
var _ Interface = (*Type)(nil)