You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: colref.rs
    path of file: ./repos/faer-rs/src/col
    
    the code of the file until where you have to start completion: use super::*;
use crate::{assert, debug_assert, diag::DiagRef, row::RowRef};

/// Immutable view over a column vector, similar to an immutable reference to a strided
/// [prim@slice].
///
/// # Note
///
/// Unlike a slice, the data pointed to by `ColRef<'_, E>` is allowed to be partially or fully
///
    
    unsafe fn overflowing_ptr_at(self, row: usize) -> GroupFor<E, *const E::Unit> {
        unsafe {
            let cond = row != self.nrows();
            let offset = (cond as usize).wrapping_neg() as isize
                & (row as isize).wrapping_mul(self.inner.stride);
            E::faer_map(
                self.as_ptr(),
                #[inline(always)]
                |ptr| ptr.offset(offset),
            )
        }
    }