<code>len(src)</code> and <code>len(dst)</code>.
As a special case, <code>copy</code> also accepts a destination argument assignable
to type <code>[]byte</code> with a source argument of a string type.
This form copies the bytes from the string into the byte slice.
</p>

<pre class="grammar">
copy(dst, src []T) int
copy(dst []byte, src string) int
</pre>

<p>
Examples:
</p>

<pre>

		}
		if r.(string) != "panic from C" {
			t.Fatal("wrong panic:", r)
		}
	}()
	C.callPanic()
}

// Test that C code can return a value if it calls a Go function that
// causes a stack copy.
func testReturnAfterGrow(t *testing.T) {
	// Use a new goroutine so that we get a small stack.
	c := make(chan int)
	go func() {
		c <- int(C.returnAfterGrow())
	}()
	if got, want := <-c, 123456; got != want {