Function einsum2_naive_into 

pub fn einsum2_naive_into<T, ID, MapA, MapB>(
    c: StridedViewMut<'_, T>,
    a: &StridedView<'_, T>,
    b: &StridedView<'_, T>,
    ic: &[ID],
    ia: &[ID],
    ib: &[ID],
    alpha: T,
    beta: T,
    map_a: MapA,
    map_b: MapB,
) -> Result<()>
where
    T: ScalarBase,
    ID: AxisId,
    MapA: Fn(T) -> T,
    MapB: Fn(T) -> T,

Binary einsum for custom scalar types using naive GEMM.

Like einsum2_into but works with any ScalarBase type (no ElementOpApply required). Uses closures map_a and map_b for per-element transformation instead of conjugation flags. Always dispatches to the naive GEMM kernel.

Views must use Identity element operations (the default).