Retain syntax
The syntactic features and operator hierarchy cannot be modified through overloading. Thus, overloaded operators have to be used in the similar way they for basic datatypes. For instance, if c1 and c2 are the objects of complex class an arithmetic assignment operator in the statement c1 +=c2;
Set c1 to the sum of c1 and c2. The overloaded version of some operator should do something analogous to the standard definition of the language. The statement should perform an operation same to the statement
C1=c1+c2;