ArrayExtensions

Partially forked from Community Toolkit.

Utility class providing high performance extension methods for working with arrays.

ArrayExtensions is a utility class that provides extension methods for arrays, including methods for getting references without bounds checks, counting occurrences of a value, checking covariance, and converting arrays to spans.

Methods

DangerousGetReference

public static ref T DangerousGetReference<T>(this T[] array)

Returns a reference to the first element within a given T[] array, with no bounds checks. The caller is responsible for performing checks in case the returned value is dereferenced.

DangerousGetReferenceAt

public static ref T DangerousGetReferenceAt<T>(this T[] array, int i)

Returns a reference to an element at a specified index within a given T[] array, with no bounds checks. The caller is responsible for ensuring the i parameter is valid.

Count

public static int Count<T>(this T[] array, T value) where T : IEquatable<T>

Counts the number of occurrences of a given value in a target T[] array instance.

IsCovariant

public static bool IsCovariant<T>(this T[] array)

Checks whether or not a given T[] array is covariant.

AsSpanFast

Only supported on .NET 5 and above. Older runtimes will use default AsSpan.

public static Span<T> AsSpanFast<T>(this T[] data)

Converts a byte array to a Span without doing a null check.

Usage

Get Reference without Bounds Checks

int[] array = new int[] { 1, 2, 3 };
ref int firstElement = ref array.DangerousGetReference();

Get Reference at Specific Index without Bounds Checks

int[] array = new int[] { 1, 2, 3 };
ref int elementAtTwo = ref array.DangerousGetReferenceAt(2);

Count Occurrences of a Value

int[] array = new int[] { 1, 2, 2, 3, 2 };
int count = array.Count(2);

Check Covariance

object[] array = new object[] { "a", "b", "c" };
bool isCovariant = array.IsCovariant<string>();

Convert Array to Span without Null Check

int[] array = new int[] { 1, 2, 3 };
Span<int> span = array.AsSpanFast();