operator==,!=(std::complex)
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <complex> | ||
| (1) | ||
| template< class T > bool operator==( const complex<T>& lhs, const complex<T>& rhs); | (until C++14) | |
| template< class T > constexpr bool operator==( const complex<T>& lhs, const complex<T>& rhs); | (since C++14) | |
| (2) | ||
| template< class T > bool operator==( const complex<T>& lhs, const T& rhs); | (until C++14) | |
| template< class T > constexpr bool operator==( const complex<T>& lhs, const T& rhs); | (since C++14) | |
| (3) | ||
| template< class T > bool operator==( const T& lhs, const complex<T>& rhs); | (until C++14) | |
| template< class T > constexpr bool operator==( const T& lhs, const complex<T>& rhs); | (since C++14) (until C++20) | |
| (4) | ||
| template< class T > bool operator!=( const complex<T>& lhs, const complex<T>& rhs); | (until C++14) | |
| template< class T > constexpr bool operator!=( const complex<T>& lhs, const complex<T>& rhs); | (since C++14) (until C++20) | |
| (5) | ||
| template< class T > bool operator!=( const complex<T>& lhs, const T& rhs); | (until C++14) | |
| template< class T > constexpr bool operator!=( const complex<T>& lhs, const T& rhs); | (since C++14) (until C++20) | |
| (6) | ||
| template< class T > bool operator!=( const T& lhs, const complex<T>& rhs); | (until C++14) | |
| template< class T > constexpr bool operator!=( const T& lhs, const complex<T>& rhs); | (since C++14) (until C++20) | |
Compares two complex numbers. Scalar arguments are treated as complex numbers with the real part equal to the argument and the imaginary part set to zero.
1-3) Compares 
lhs and rhs for equality.4-6) Compares 
lhs and rhs for inequality.Parameters
| lhs, rhs | - | the arguments to compare: either both complex numbers or one complex and one scalar of matching type (float, double, long double) | 
Return value
1-3) true if respective parts of 
lhs are equal to rhs, false otherwise.4-6) !(lhs == rhs)
Example
| This section is incomplete Reason: no example |