std::atan(std::complex)

From cppreference.com
Defined in header <complex>
template< class T >
complex<T> atan( const complex<T>& z );
(since C++11)

Computes complex arc tangent of a complex value z. Branch cut exists outside the interval [−i ; +i] along the imaginary axis.

[edit] Parameters

z - complex value

[edit] Return value

Complex arc tangent of z in the range [−iπ/2 ; +iπ/2] along the imaginary axis.

[edit] See also

computes arc sine of a complex number (arcsin(z))
(function template)
computes arc cosine of a complex number (arccos(z))
(function template)