Implement Span<T> in Unity

Question

I'm trying to use Span in Unity.

I understand that System.Memory is not supported yet, but I'd like to implement it anyway.

I directly downloaded the library from NuGet. I got the System.Memory.dll from netstandard2.0 folder in the nuget package and dragged it in the project Assets/Scripts folder.

But I get this error, and I cannot use it in my IDE (Rider).

Assembly 'Assets/System.Memory.dll' will not be loaded due to errors: Unable to resolve reference 'System.Runtime.CompilerServices.Unsafe'. Is the assembly missing or incompatible with the current platform?

My question is: how can I use Span in Unity?

Unity Version: Unity 2019.1.7f.
OS: Windows

As the error says, you're missing System.Runtime.CompilerServices.Unsafe. Look at the "Dependencies" tab on NuGet to see what dependencies it needs. You'll need to check all of your dependencies' dependencies too. Probably easier to follow stackoverflow.com/a/53458099/1086121 — canton7
Why -1? After some hours of search I made my question here, then after other hours I found my answer (and I noted this answer was asked in multiple places on Unity Forum so it was not just my issue). An answer here might have saved me the hours of the second part of the search. Is this somehow wrong? — Jack Mariani

Jack Mariani Jack Mariani · Accepted Answer · 2019-07-04T14:43:28

Nuget may generate issues in Unity.

The solution is to directly download the dll.

Get the library from the direct download => Download Package
Import the System.Memory.dll from lib/netstandartd2.0 folder into the Project Window
Select System.Memory.dll in the Project Window then Disable "Validate Reference"

I took the info from unity forum and applied to my situation. (In the forum they are using Unity Packages, while I'm just setting the library on the Assets)

Implement Span<T> in Unity

2 Answers