NativeSpan.cs

using System;
using System.Runtime.InteropServices;

namespace NativeSpan
{
	/// <summary>Allows manual memory management without GC in a manner that's still mostly safe</summary>
	ref struct NativeSpan<T> where T : unmanaged
	{
		readonly IntPtr nativePointer;
		readonly int length;

		public NativeSpan( int length )
		{
			if( length <= 0 )
				throw new ArgumentException();
			nativePointer = Marshal.AllocHGlobal( Marshal.SizeOf<T>() * length );
			if( nativePointer == default )
				throw new OutOfMemoryException();
			this.length = length;
		}

		public void Dispose()
		{
			Marshal.FreeHGlobal( nativePointer );
		}

		public Span<T> span
		{
			get
			{
				unsafe
				{
					return new Span<T>( (void*)nativePointer, length );
				}
			}
		}
	}

	static class Program
	{
		static void Main( string[] args )
		{
			using( var ns = new NativeSpan<int>( 11 ) )
			{
				foreach( ref var i in ns.span )
					i = 33;
			}
		}
	}
}