Use package to annotate types intead of comments.

[egonelbre]

Instead of using comments to annotate types, use either function calls or stub interfaces.

Either of these could work:

type Letter byte

var _ enum.Exhaustive = Letter(0)

type Letter byte

var _ = enum.Exhaustive(Letter(0))

This would allow to specify the different options more nicely or suppressing the error messages.

[egonelbre]

For exceptions to the default behavior in switches:

switch enum.Exhaustive(xyz); xyz {

For exceptions to the default behavior in func declarations:

func Example(xyz Value) {
    enum.Exhaustive(xyz)
}