<pre>
const (
	c1 = imag(2i)                    // imag(2i) = 2.0 is a constant
	c2 = len([10]float64{2})         // [10]float64{2} contains no function calls
	c3 = len([10]float64{c1})        // [10]float64{c1} contains no function calls
	c4 = len([10]float64{imag(2i)})  // imag(2i) is a constant and no function call is issued
	c5 = len([10]float64{imag(z)})   // invalid: imag(z) is a (non-constant) function call
)
var z complex128

			panic("bad x")
		}
	}
}

func variadic(x ...interface{}) {}

func testBlocking(t *testing.T) {
	c := make(chan int)
	go func() {
		for i := 0; i < 10; i++ {
			c <- <-c
		}
	}()
	nestedCall(func() {
		for i := 0; i < 10; i++ {
			c <- i
			if j := <-c; j != i {
				t.Errorf("out of sync %d != %d", j, i)
			}
		}
	})
}