Counted arrays allow variable-length arrays to be encoded as homogeneous elements: the element count n (an unsigned integer) is followed by each array element, starting with element 0 and progressing through element n-1.
The declaration for variable-length arrays follows this form:
type-name identifier<m>;
or
type-name identifier<>;
The constant m specifies the maximum acceptable element count of an array. If m is not specified, it is assumed to be (2**32) - 1.
Counted Array
It is an error to encode a length greater than the maximum described in the specification.