/// Allows you create a cycle with mutable conditions.
/// # Arguments list:
/// - cond: mutable condition (for example, `i!=array.len()`)
/// - code: the following code
/// # Examples
/// ```
/// fn main() {
/// let mut v = vec![1i32,2,3,4,5];
///
/// let mut i = 0;
/// while_mut!{
/// i<v.len(),
/// {
/// v.remove(0);
/// println!("{} {} {}", v[0], v.len(), i);
/// i += 1;
/// }
/// }
/// }
/// ```
=>
}