Power of two

#[test]
fn test_2_itself() {
    let start = std::time::Instant::now();
    let val = Solution::is_power_of_two(2);
    let expected = true;
    log_result!(val == expected, "test_2_itself", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn test_example_1() {
    let start = std::time::Instant::now();
    let val = Solution::is_power_of_two(1);
    let expected = true;
    log_result!(val == expected, "test_example_1", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn test_example_2() {
    let start = std::time::Instant::now();
    let val = Solution::is_power_of_two(16);
    let expected = true;
    log_result!(val == expected, "test_example_2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn test_example_3() {
    let start = std::time::Instant::now();
    let val = Solution::is_power_of_two(3);
    let expected = false;
    log_result!(val == expected, "test_example_3", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn test_large_power_of_2() {
    let start = std::time::Instant::now();
    let val = Solution::is_power_of_two(1024);
    let expected = true;
    log_result!(val == expected, "test_large_power_of_2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn test_negative_number() {
    let start = std::time::Instant::now();
    let val = Solution::is_power_of_two(-16);
    let expected = false;
    log_result!(val == expected, "test_negative_number", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn test_not_power_of_2() {
    let start = std::time::Instant::now();
    let val = Solution::is_power_of_two(100);
    let expected = false;
    log_result!(val == expected, "test_not_power_of_2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn test_zero() {
    let start = std::time::Instant::now();
    let val = Solution::is_power_of_two(0);
    let expected = false;
    log_result!(val == expected, "test_zero", start, &expected, &val);
    assert_eq!(val, expected);
}