Constructors. Constructs an object. @li **(1)**--**(3)** the object is empty. @li **(4)** the object is filled with values in the range `[first, last)`. @li **(5)**, **(6)** the object is filled with copies of the values in `init`. @li **(7)**, **(8)** the object is filled with copies of the elements of `other`.