Function atan

src/fl/math/math.h:385–385

// atan
inline float atanf(float value) FL_NOEXCEPT { return atan_impl_float(value); }
inline double atan(double value) FL_NOEXCEPT { return atan_impl_double(value); }
template<typename T> inline typename enable_if<is_integral<T>::value, float>::type
atan(T value) FL_NOEXCEPT { return atan_impl_float(static_cast<float>(value)); }