how can sort this unary operator and then sort them

 

Unary negation operator ( - ) (to be implemented by students)

Numbers operator-()const

This unary operator (that is incapable of modifying the current object) will return a descending sorted copy of the Numbers object.

Unary plus operator ( + ) (to be implemented by students)

 

Numbers operator+()const

This unary operator (that is incapable of modifying the current object) will return an ascending sorted copy of the Numbers object.