# Function from_raw_parts_mut

1.6.0 (const: 1.83.0) · Source

    pub const unsafe fn from_raw_parts_mut<'a, T>(
        data: *mut T,
        len: usize,
    ) -> &'a mut [T]

Expand description

Performs the same functionality as `from_raw_parts`, except that a mutable slice is returned.

## §Safety

Behavior is undefined if any of the following conditions are violated:

- `data` must be non-null, valid for both reads and writes for `len * size_of::<T>()` many bytes, and it must be properly aligned. This means in particular:

  - The entire memory range of this slice must be contained within a single allocation! Slices can never span across multiple allocations.
  - `data` must be non-null and aligned even for zero-length slices or slices of ZSTs. One reason for this is that enum layout optimizations may rely on references (including slices of any length) being aligned and non-null to distinguish them from other data. You can obtain a pointer that is usable as `data` for zero-length slices using `NonNull::dangling()`.

- `data` must point to `len` consecutive properly initialized values of type `T`.

- The memory referenced by the returned slice must not be accessed through any other pointer (not derived from the return value) for the duration of lifetime `'a`. Both read and write accesses are forbidden.

- The total size `len * size_of::<T>()` of the slice must be no larger than `isize::MAX`, and adding that size to `data` must not “wrap around” the address space. See the safety documentation of `pointer::offset`.