debian man page for array_length

array_length(3) 					     Library Functions Manual						   array_length(3)

NAME
       array_length - get number of allocated members in array

SYNTAX
       #include <array.h>

       int64 array_length(array* x,uint64 membersize);

	 array x;
	 int64 members = array_length(&x,sizeof(t));

DESCRIPTION
       array_length returns the number of initialized bytes in x, divided by the size of t. In other words, array_get will succeed for positions 0
       through array_length-1; it will fail for position array_length.

       If x is unallocated, array_length and array_bytes return 0.

SEE ALSO
       array_allocate(3), array_get(3), array_fail(3), array_bytes(3)

																   array_length(3)