results:   []string{"c1", "c2", "c3", "c5", "c4"},
		},
		{
			callbacks: []callback{{h: c1}, {h: c2, before: "c4", after: "c5"}, {h: c3}, {h: c4}, {h: c5}},
			results:   []string{"c1", "c5", "c2", "c3", "c4"},
		},
		{
			callbacks: []callback{{h: c1, after: "c3"}, {h: c2, before: "c4", after: "c5"}, {h: c3, before: "c5"}, {h: c4}, {h: c5}},
			results:   []string{"c3", "c1", "c5", "c2", "c4"},

	if c4 != C4 {
		println("opcode x", c4, C4)
		panic("fail")
	}

	c5 := c1 + r
	if c5 != C5 {
		println("opcode x", c5, C5)
		panic("fail")
	}

	c6 := c1 + i
	if c6 != C6 {
		println("opcode x", c6, C6)
		panic("fail")
	}

	ca := c5 + c6
	if ca != Ca {
		println("opcode x", ca, Ca)
		panic("fail")
	}

	cb := c5 - c6
	if cb != Cb {
		println("opcode x", cb, Cb)
		panic("fail")
	}

func main() {
	if c1 != 0 {
		panic(c1)
	}
	if c2 != 0 {
		panic(c2)
	}

	if c3 != 0 {
		panic(c3)
	}
	if c4 != 1 {
		panic(c4)
	}

	const c5 = iota
	const c6 = iota

	if c5 != 0 {
		panic(c5)
	}
	if c6 != 0 {
		panic(c6)
	}

// license that can be found in the LICENSE file.

package main

const (
	c0   = 1 << 100
	c1   = c0 * c0
	c2   = c1 * c1
	c3   = c2 * c2 // GC_ERROR "overflow"
	c4   = c3 * c3
	c5   = c4 * c4
	c6   = c5 * c5
	c7   = c6 * c6
	c8   = c7 * c7
	c9   = c8 * c8
	c10  = c9 * c9
	c11  = c10 * c10
	c12  = c11 * c11
	c13  = c12 * c12
	c14  = c13 * c13 // GCCGO_ERROR "overflow"
	c15  = c14 * c14

00000020  30 06 b7 7b 17 a9 79 30  2a d8 57 20 c5 5c ed 86  |0..{..y0*.W .\..|
00000030  15 f4 3b c8 d2 5f 7a 80  2a 6a cd 40 c2 da 6f a8  |..;.._z.*j.@..o.|
00000040  cd d7 e7 bf 48 bd fb a1  e9 4b 9b a9 00 04 00 2f  |....H....K...../|
00000050  00 ff 01 00 00 b9 00 23  00 79 00 00 00 00 00 00  |.......#.y......|
00000060  00 00 00 00 00 00 00 00  00 00 94 6f 2d b0 ac 51  |...........o-..Q|
00000070  ed 14 ef 68 ca 42 c5 4c  85 f6 26 0d a4 ad a8 f5  |...h.B.L..&.....|

00000390  75 6c 62 86 07 50 ee 1f  ef 3b 55 fd 68 44 47 27  |ulb..P...;U.hDG'|
000003a0  07 c1 53 b5 13 c5 e0 a4  d6 9e 8a 3c 78 a0 04 b7  |..S........<x...|
000003b0  08 17 03 03 00 45 6b fc  53 20 43 7a f3 26 2f fc  |.....Ek.S Cz.&/.|
000003c0  97 0e d3 09 f0 d9 c5 46  af be e4 c5 06 31 6f 6c  |.......F.....1ol|
000003d0  5f 11 ec 4a c5 d5 02 50  aa d5 28 98 60 f1 79 82  |_..J...P..(.`.y.|

type (
	V0 = V1
	V1 = (V2)
	V2 = (V3)
	V3 = T0
)

func (V1) n() {}

// cycles
type C0 struct {
	f1 C1
	f2 C2
}

type (
	C1 *C0
	C2 = C1
)

type (
	C5 struct {
		f *C6
	}
	C6 = C5

00000300  1e 8f 5a 28 b1 5a 88 46  48 7e 40 93 f2 38 9d 33  |..Z(.Z.FH~@..8.3|
00000310  6b b5 92 ed 6d 44 07 03  c8 77 ee 3a 80 37 1e f9  |k...mD...w.:.7..|
00000320  4d 5c 2b 6d c5 15 07 b2  7c eb c5 f5 c5 14 dd 16  |M\+m....|.......|
00000330  03 02 00 04 0e 00 00 00                           |........|
>>> Flow 3 (client to server)
00000000  16 03 02 00 25 10 00 00  21 20 2f e5 7d a3 47 cd  |....%...! /.}.G.|

00000270  6e c2 a6 95 60 f3 86 20  29 a6 a8 8f b3 b0 0d 57  |n...`.. )......W|
00000280  d2 1e 4a b9 d2 63 33 09  f9 c5 87 94 89 c5 fd 2e  |..J..c3.........|
00000290  de b3 f0 0e 7b 4e 3e d6  21 b4 3b 58 bd 2a 35 49  |....{N>.!.;X.*5I|
000002a0  5e b0 f4 5a ca 58 dc a5  8b 45 a5 d1 7b 13 b2 00  |^..Z.X...E..{...|
000002b0  52 c4 b2 6c d1 9a b8 c5  1b fe 17 03 03 00 35 c9  |R..l..........5.|

00000060  c5 70 0f 08 83 48 e9 48  ef 6e 50 8b 05 7e e5 84  |.p...H.H.nP..~..|
00000070  25 fa 55 c7 ae 31 02 27  00 ef 3f 98 86 20 12 89  |%.U..1.'..?.. ..|
00000080  91 59 28 b4 f7 d7 af d2  69 61 35 14 03 03 00 01  |.Y(.....ia5.....|
00000090  01 16 03 03 00 24 fd 67  40 11 7e 4d 8f bb 87 e8  |.....$.g@.~M....|
000000a0  c3 1f e8 b0 15 17 3a f4  6f 5f 87 b2 50 c5 92 e4  |......:.o_..P...|