Function real_class_count 

pub fn real_class_count(
    degree: usize,
    gens: &[Perm],
    cap: usize,
) -> Option<usize>

The number of real conjugacy classes — those closed under inversion (C = C⁻¹). By Burnside’s theorem this equals the number of real-valued irreducible characters. None when |G| > cap.