x.go:13: cannot use t (type T) as type Reader in assignment:
	T does not implement Reader (Read method requires pointer receiver)
x.go:19: cannot use q (type Q) as type Reader in assignment:
	Q does not implement Reader (missing Read method)
		have read()
		want Read()
x.go:22: cannot use z (type int) as type Reader in assignment:
	int does not implement Reader (missing Read method)

x.go:24: too many arguments to conversion to complex: complex(1, 3)

R=ken2
CC=golang-dev
https://golang.org/cl/1736041