com.unity.demoteam.digital-human/Runtime/MeshTools/ArrayUtils.cs

using Unity.Collections;
using Unity.Mathematics;

public static class ArrayUtils
{
    //PACKAGETODO remove begin
    public static void ResizeChecked<T>(ref T[] array, int length)
    {
        if (array == null)
            array = new T[length];
        if (array.Length != length)
            System.Array.Resize(ref array, length);
    }

    public static void ResizeCheckedIfLessThan<T>(ref T[] array, int length)
    {
        if (array == null)
            array = new T[length];
        if (array.Length < length)
            System.Array.Resize(ref array, length);
    }

    public static void CopyChecked<T>(T[] arraySrc, ref T[] arrayDst, int length)
    {
        ResizeCheckedIfLessThan(ref arrayDst, length);
        System.Array.Copy(arraySrc, arrayDst, length);
    }

    public static void ClearChecked<T>(T[] array)
    {
        if (array != null)
            System.Array.Clear(array, 0, array.Length);
    }
    //PACKAGETODO remove end

    public static void Realloc<T>(ref NativeArray<T> array, int length, Allocator allocator = Allocator.Persistent) where T : struct
    {
        NativeArray<T> dst = new NativeArray<T>(length, allocator, NativeArrayOptions.UninitializedMemory);
        NativeArray<T>.Copy(array, dst, math.min(array.Length, length));
        array.Dispose();
        array = dst;
    }

    public static void ReallocChecked<T>(ref NativeArray<T> array, int length, Allocator allocator = Allocator.Persistent) where T : struct
    {
        if (array.IsCreated == false)
            array = new NativeArray<T>(length, allocator, NativeArrayOptions.UninitializedMemory);
        if (array.Length != length)
            Realloc(ref array, length, allocator);
    }

    public static void ReallocCheckedIfLessThan<T>(ref NativeArray<T> array, int length, Allocator allocator = Allocator.Persistent) where T : struct
    {
        if (array.IsCreated == false)
            array = new NativeArray<T>(length, allocator, NativeArrayOptions.UninitializedMemory);
        if (array.Length < length)
            Realloc(ref array, length, allocator);
    }

    public static void CopyChecked<T>(in NativeArray<T> arraySrc, ref NativeArray<T> arrayDst, Allocator allocator = Allocator.Persistent) where T : struct
    {
        ReallocCheckedIfLessThan(ref arrayDst, arraySrc.Length, allocator);
        NativeArray<T>.Copy(arraySrc, arrayDst);
    }
}