cpp/numeric/complex/atan

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

Return value
If no errors occur, complex arc tangent of is returned, in the range of a strip unbounded along the imaginary axis and in the interval $[−π/2, +π/2]$ along the real axis.

Errors and special cases are handled as if the operation is implemented by, where is the imaginary unit.