explicit vector(const Allocator&);
Effects: Constructs an empty vector, using the specified allocator.
Complexity: Constant.
explicit vector(size_type n, const Allocator& = Allocator());
Effects: Constructs a vector with n default-inserted elements using the specified allocator.
Requires: T shall be DefaultInsertable into *this.
Complexity: Linear in n.
vector(size_type n, const T& value,
const Allocator& = Allocator());
Effects: Constructs a vector with n copies of value, using the specified allocator.
Requires: T shall be CopyInsertable into *this.
Complexity: Linear in n.
template <class InputIterator>
vector(InputIterator first, InputIterator last,
const Allocator& = Allocator());
Effects: Constructs a vector equal to the range [first,last), using the specified allocator.
Complexity: Makes only N calls to the copy constructor of T (where N is the distance between first and last) and no reallocations if iterators first and last are of forward, bidirectional, or random access categories. It makes order N calls to the copy constructor of T and order log(N) reallocations if they are just input iterators.