for _, test := range testCases {
		a := []byte(test.a)
		actual := f(a, test.b)
		if actual != test.i {
			t.Errorf("%s(%q,%q) = %v; want %v", funcName, a, test.b, actual, test.i)
		}
	}
}

func TestIndex(t *testing.T)     { runIndexTests(t, Index, "Index", indexTests) }
func TestLastIndex(t *testing.T) { runIndexTests(t, LastIndex, "LastIndex", lastIndexTests) }