Rental.cs

using System;
using System.Buffers;

namespace __
{
    public readonly struct Rental<T> : IDisposable
    {
        readonly T[] _array;
        readonly bool _clear;
        readonly int _length;
        readonly ArrayPool<T> _pool;

        public Rental(int length) :
            this(length, ArrayPool<T>.Shared)
        {
        }

        public Rental(int length, ArrayPool<T> pool) :
            this(length, pool, false)
        {
        }

        public Rental(int length, ArrayPool<T> pool, bool clearOnReturn)
        {
            _array = (_pool = pool)
                .Rent(_length = length);
            _clear = clearOnReturn;
        }

        public void Dispose()
        {
            _pool.Return(_array, _clear);
        }

        public Memory<T> AsMemory()
        {
            return _array.AsMemory(0, _length);
        }

        public Span<T> AsSpan()
        {
            return _array.AsSpan(0, _length);
        }
    }
}