BlockingQueue() : BlockingQueue(kInfiniteQueueSize) {} what's this meaning?

     template <typename T>
    class BlockingQueue {
     public:
      static constexpr size_t kInfiniteQueueSize = 0;
    
      // Constructs a blocking queue with infinite queue size.
      BlockingQueue() : BlockingQueue(kInfiniteQueueSize) {}
}

Hi Dude, as usual we initialize constructor parameters such like

 class a{
     private:
     int b_;
     char c_;
     public:
     c(int b, char c):b_(b),c_(c){}
}

However, in this class BlockingQueue() : BlockingQueue(kInfiniteQueueSize) {} is initialize the constructor ? or something else?