switch doesn't work for a type derived from bool

[gopherbot]

by bslesinsky:

What steps will reproduce the problem?

type Color bool;
const (
    Black = false;
    White = true;
)

func (c Color) String() string {
    switch c {
    case White: return "White";
    case Black: return "Black";
    }
    panic("not reachable");
}


What is the expected output? What do you see instead?

I think this should compile, but I get: 

gongo.go:66: case true (type bool) in Color switch
gongo.go:66: case false (type bool) in Color switch


What is your $GOOS?  $GOARCH?

$ echo $GOOS $GOARCH
darwin 386

Which revision are you using?  (hg identify)

$ hg identify
44699e529c44+ tip

An easy workaround is to rewrite it like this:

    switch {
    case c == White: return "White";
    case c == Black: return "Black";
    }

[gopherbot]

Comment 1 by bslesinsky:

Never mind. The correct way to write this is:
type Color bool;
const (
    Black = Color(false);
    White = Color(true);
)
func (c Color) String() string {
    switch (c) {
    case White: return "White";
    case Black: return "Black";
    }
    panic("not reachable");
}

[gopherbot]

Comment 2 by eadfrith:

The types Color and bool are assignment compatible so you don't really need the
conversion - you just need to specify the Color type in the const declaration:
const (
  Black, White Color = false, true;
)

[griesemer]

Comment 3:

Issue closed - this is not a bug. The code below works as expected.
package main
type Color bool;
const (
    Black Color = false;
    White Color = true;
)
func (c Color) String() string {
    switch c {
    case White: return "White";
    case Black: return "Black";
    }
    panic("not reachable");
}
func main() {
    println(Black.String());
    println(White.String());
}

Owner changed to g...@golang.org.

Status changed to Invalid.