Type Definition ndarray::ArrayViewMut

source ·
pub type ArrayViewMut<'a, A, D> = ArrayBase<ViewRepr<&'a mut A>, D>;
Expand description

A read-write array view.

An array view represents an array or a part of it, created from an iterator, subview or slice of an array.

The ArrayViewMut<'a, A, D> is parameterized by 'a for the scope of the borrow, A for the element type and D for the dimensionality.

Array views have all the methods of an array (see ArrayBase).

See also ArrayView.

Implementations§

Methods for read-write array views.

Create a read-write array view borrowing its data from a slice.

Checks whether dim and strides are compatible with the slice’s length, returning an Err if not compatible.

use ndarray::ArrayViewMut;
use ndarray::arr3;
use ndarray::ShapeBuilder;

let mut s = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
let mut a = ArrayViewMut::from_shape((2, 3, 2).strides((1, 4, 2)),
                                     &mut s).unwrap();

a[[0, 0, 0]] = 1;
assert!(
    a == arr3(&[[[1, 2],
                 [4, 6],
                 [8, 10]],
                [[1, 3],
                 [5, 7],
                 [9, 11]]])
);
assert!(a.strides() == &[1, 4, 2]);

Create an ArrayViewMut<A, D> from shape information and a raw pointer to the elements.

Unsafe because caller is responsible for ensuring all of the following:

  • The elements seen by moving ptr according to the shape and strides must live at least as long as 'a and must not be aliased for the duration of 'a.

  • ptr must be non-null and aligned, and it must be safe to .offset() ptr by zero.

  • It must be safe to .offset() the pointer repeatedly along all axes and calculate the counts for the .offset() calls without overflow, even if the array is empty or the elements are zero-sized.

    In other words,

    • All possible pointers generated by moving along all axes must be in bounds or one byte past the end of a single allocation with element type A. The only exceptions are if the array is empty or the element type is zero-sized. In these cases, ptr may be dangling, but it must still be safe to .offset() the pointer along the axes.

    • The offset in units of bytes between the least address and greatest address by moving along all axes must not exceed isize::MAX. This constraint prevents the computed offset, in bytes, from overflowing isize regardless of the starting point due to past offsets.

    • The offset in units of A between the least address and greatest address by moving along all axes must not exceed isize::MAX. This constraint prevents overflow when calculating the count parameter to .offset() regardless of the starting point due to past offsets.

  • The product of non-zero axis lengths must not exceed isize::MAX.

Convert the view into an ArrayViewMut<'b, A, D> where 'b is a lifetime outlived by 'a'.

Split the array view along axis and return one mutable view strictly before the split and one mutable view after the split.

Panics if axis or index is out of bounds.

Return the array’s data as a slice, if it is contiguous and in standard order. Return None otherwise.

Trait Implementations§

Implementation of ArrayViewMut::from(&mut A) where A is an array.

Create a read-write array view of the array.

Converts to this type from the input type.

Implementation of ArrayViewMut::from(&mut S) where S is a slice or slicable.

Create a one-dimensional read-write array view of the data in slice.

Panics if the slice length is greater than isize::MAX.

Converts to this type from the input type.

Convert a mutable array view to a mutable reference of a element.

This method is like IndexMut::index_mut but with a longer lifetime (matching the array view); which we can only do for the array view and not in the Index trait.

See also the get_mut method which works for all arrays and array views.

Panics if index is out of bounds.

Convert a mutable array view to a mutable reference of a element, with checked access.

See also the get_mut method which works for all arrays and array views.

Convert a mutable array view to a mutable reference of a element without boundary check.

See also the uget_mut method which works for all arrays and array views.

Note: only unchecked for non-debug builds of ndarray.

The type of the reference to the element that is produced, including its lifetime. Read more
The type of the elements being iterated over.
Which kind of iterator are we turning this into?
Creates an iterator from a value. Read more
The element produced per iteration.
Dimension type
This trait is private to implement; this method exists to make it impossible to implement outside the crate. Read more