Using static opCall instead of the default constructor.

[Jaehunt]

Hello, I am trying to using static opCall instead of the default 
constructor.

When I run it, I got "Error: need 'this' to access member A".
How to fix it?

Here is my code.

struct PriorityQueue(T) {
        static const int DEFAULT_QueueSIZE = 1;
        T[] A;
        int num;
        
        this(this){
                A = A.dup;
        }
        
        static PriorityQueue opCall() {
                
                A =  new T[DEFAULT_QueueSIZE];  // Error
                num = 1;                        // Error
                
                PriorityQueue priorityQueue;
                
                return priorityQueue;
        }
        
        bool empty() { return num == 0; }
        
        void insert( T item) {
                if( A.length == num ) A.length *= 2;
                A[ num++] = item;
        }
        
        T extractMax() {
                A.sort;
                return A[ --num];
        }
}