Bug IL2CPP doesn't support ReadOnlyMemory<T> or ReadOnlySpan<byte> method parameters

I have a C# .netstandard2.1 project https://github.com/edjCase/ICP.NET/ that game developers are trying to use with their Unity games but there is a problem when compiling to WebGL/IL2CPP. Any instance where a method is called that has ReadOnlyMemory<T> (readonly struct) or ReadOnlySpan<byte> (readonly ref struct) it gives the following message:
```
Building Library\Bee\artifacts\WebGL\GameAssembly\release_WebGL_wasm\8hlh_.ICP.Agent.o failed with output:
C:\Git\icp.net_demo\ICP_demo_unity\Library\Bee\artifacts\WebGL\il2cppOutput\cpp\EdjCase.ICP.Agent.cpp:10541:3: error: no matching function for call to 'CborReader__ctor_m5191B60B1242ACF099DE8349ED037D0A17E36DD4'
CborReader__ctor_m5191B60B1242ACF099DE8349ED037D0A17E36DD4(L_15, L_14, 1, (bool)0, NULL);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C:\Git\icp.net_demo\ICP_demo_unity\Library\Bee\artifacts\WebGL\il2cppOutput\cpp\EdjCase.ICP.Agent.cpp:3562:41: note: candidate function not viable: no known conversion from 'ReadOnlyMemory_1_t63F301BF893B0AB689953D86A641168CA66D2399' to 'ReadOnlyMemory_1_t43203E8B19A7F4A97A9A49363F67C206E8B058FE' for 2nd argument
IL2CPP_EXTERN_C IL2CPP_METHOD_ATTR void CborReader__ctor_m5191B60B1242ACF099DE8349ED037D0A17E36DD4 (CborReader_tD16D04772AB3E74EA1866DBEC07FFFD66AC95CE5* __this, ReadOnlyMemory_1_t43203E8B19A7F4A97A9A49363F67C206E8B058FE ___0_data, int32_t ___1_conformanceMode, bool ___2_allowMultipleRootLevelValues, const RuntimeMethod* method) ;


```
Where the method signature is `(ReadOnlyMemory<byte> data, CborConformanceMode conformanceMode = CborConformanceMode.Strict, bool allowMultipleRootLevelValues = false)`

There are a few other dead forum posts that have similar issues:
https://forum.unity.com/threads/il2...call-linking-to-addressable-function.1113328/
https://forum.unity.com/threads/no-...l-with-il2cpp-in-unity-2019-4-8f1-lts.963761/

Any thoughts on how to resolve this or and potential fixes that can happen.

Using mono instead of IL2CPP has no issues

 

I tried that with no luck. It has the same issue.
From what I understand this a compile time conversion issue between IL and CPP using IL2CPP. It doesnt seem to like readonly structs or something

 

Done. Thank you

 

CASE IN-37985

 

Hello, seems like my issue is the same. I've been trying to use ImageSharp in Unity 2022.2.14. https://github.com/SixLabors/ImageSharp/tree/release/1.0.x

All is good in the editor but it always fails on WebGL:



Eventually managed to track it down this line after days of debugging.



So signature eventually becomes `this.EncodePixelRow<Rgb32>(ReadonlySpan<Rgb32>, IndexedImageFrame<Rgb32>, int)`.

Seems like it was fixed for ReadOnlySpan<> fields.
https://forum.unity.com/threads/il2cpp-readonlyspan-feilds-crash.1338875/

Do we have a timeline for a fix if this has been already reproduced? Thanks!

 

Just now I've done a test and I've replaced the ReadOnlySpan<TPixel> method parameters to TPixel[] and it worked. Anytime I'll hit over a Span<> or ReadOnlySpan<> method parameter I'm having "null function or function signature mismatch". So I think we can add this note to your investigation.

 

I have a bug report in with Unity but it has not been reproduced at this point. Hopefully today we'll see something

 

@JoshPeterson is there any update on the status of this fix?

We're currently blocked from doing a major game release due to this bug.