std::arg(std::complex)
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <complex> | ||
| template< class T >  T arg( const complex<T>& z ); | (1) | |
| long double arg( long double z ); | (2) | (since C++11) | 
| template< class DoubleOrIngeter > double arg( DoubleOrInteger z ); | (3) | (since C++11) | 
| float arg( float z ); | (4) | (since C++11) | 
Returns the phase angle (in radians) of the complex number z, i.e. atan2(std::imag(z), std::real(z)).
(since C++11)Additional overloads are provided for float, double, long double, and all integer types, which are treated as complex numbers with zero imaginary component.
[edit] Parameters
| z | - | complex value | 
[edit] Return value
the phase angle of z
[edit] See also
| returns the magnitude of a complex number (function template) | |
| constructs a complex number from magnitude and phase angle (function template) | |
| arc tangent, using signs to determine quadrants (function) | |
| applies the function std::atan2 to a valarray and a value (function template) | |
| C documentation for carg | |


