//! Small unsafe helpers for writing into pre-sized vectors.
/// Writes `value` into `vec[index]` without bounds checks or drop handling.
///
/// The caller must guarantee that `index` is in-bounds for the already-initialized
/// backing allocation and that writing here does not leak an old value.
pub unsafe
/// Copies raw bytes into a pre-sized byte vector at `offset` without bounds checks.
///
/// The caller must guarantee that `offset..offset + bytes.len()` is valid inside
/// the existing allocation.
pub unsafe