This module provides a replacement for Haskell's atan2. The problem is that Haskell's standard implementation of atan2 depends on the RealFloat class, which limits its applicability. So we provide a new ArcTan2 class with an arctan2 function.

Unlike Haskell's atan2, the arctan2 function may not take signed zeros and signed infinities into account. But it works at fixed-precision types such as FixedPrec.