What methods are called behind the use of objects

• During the transfer of function parameters , Objects are passed by reference first , Don't pass by value .（ Reduce the construction and destruction of formal parameter objects ）
• When the function returns an object , A zero hour object should be returned first , Instead of returning a defined object
  
• When accepting a function call whose return value is an object , Accept preferentially in the way of initialization , Don't accept in the way of assignment .
  

The pointer is not secure , But references can .

Cannot return a pointer or reference to a local or temporary object