std::complex::real
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | T real() const; | (1) | |
| void real( T value ); | (2) | |
Accesses the real part of the complex number.
1) Returns the real part.
2) Sets the real part to value.
[edit] Parameters
| value | - | the value to set the real part to | 
[edit] See also
| accesses the imaginary part of the complex number (public member function) | |