# Function std::ptr::swap_nonoverlapping

1.27.0 (const: unstable) · source ·

    pub unsafe fn swap_nonoverlapping<T>(x: *mut T, y: *mut T, count: usize)

Expand description

Swaps `count * size_of::<T>()` bytes between the two regions of memory beginning at `x` and `y`. The two regions must not overlap.

The operation is “untyped” in the sense that data may be uninitialized or otherwise violate the requirements of `T`. The initialization state is preserved exactly.

## Safety

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

- Both `x` and `y` must be valid for both reads and writes of `count * size_of::<T>()` bytes.

- Both `x` and `y` must be properly aligned.

- The region of memory beginning at `x` with a size of `count * size_of::<T>()` bytes must not overlap with the region of memory beginning at `y` with the same size.

Note that even if the effectively copied size (`count * size_of::<T>()`) is `0`, the pointers must be non-null and properly aligned.

## Examples

Basic usage:

    use std::ptr;

    let mut x = [1, 2, 3, 4];
    let mut y = [7, 8, 9];

    unsafe {
        ptr::swap_nonoverlapping(x.as_mut_ptr(), y.as_mut_ptr(), 2);
    }

    assert_eq!(x, [7, 8, 3, 4]);
    assert_eq!(y, [1, 2, 9]);

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