What is an r-value reference? Why might it be useful? List three reasons why a language implementation might implement a parameter as a closure. What is a conformant (open) array? What are default...

What is an r-value reference? Why might it be useful? List three reasons why a language implementation might implement a parameter as a closure. What is a conformant (open) array? What are default parameters? How are they implemented? What are named (keyword) parameters? Why are they useful?