Mono 5.10.0+ Unity3D integration (for C# 7 support)?

From this page: http://www.mono-project.com/docs/about-mono/releases/5.10.0/, it seems that Mono has gained better C# 7 support as of 2018, and I'm assuming that the upcoming release of Mono 5.12.0 would be even better. What's the plan for Unity3D to integrate the latest greatest Mono releases so C# 7 can finally be "officially" possible in Unity3D?

 

It's already done. 2018.1.0b10 has `Mono C# compiler version 5.11.0.0`.

 

I just installed b10, and this is confirmed. On a related note: is it easy to add an option in the "Player Settings" under "Configuration", where "Scripting Runtime Version" locates, another option is added: "C# Language Version", which contains all the currently *valid* Mono supported C# language versions: ISO-1, ISO-2, 3, 4, 5, 6, Default, or Experimental (extracted from mcs --help), so if I chose "Experimental", the generated .csproj file(s) will have the version specified under the "<LangVersion>" section, while currently it's hard coded to "6" for "Stable (.NET 4.x Equivalent)". And there has been issues to manually change "LangVersion" manually - I even tried, as a hack, the mcs.rsp to specify "-langversion: Experimental", and it didn't seem to work for me.

 

I use some #C 7.X features (ref struct, ref return, value tuples) since 2018.1.0b6 or 7. I also use netstandard 2.0 and some cool pre-release libs from Nuget: System.Memory, System.Runtime.CompilerServices.Unsafe etc. They all work, but with every new beta be ready to spend some time fixing some errors and minor issues.

In 2018.1.0b10 you cannot get all C# 7.X features, only those listed there: https://github.com/mono/mono/issues/6854

To enable C# 7.2:

1. Put `-langversion:7.2` in mcs.rsp.

2. Put `<PropertyGroup><LangVersion>7.2</LangVersion> </PropertyGroup>` in csproj files.

Of course, manually editing csproj is a bad idea. I use Rider EAP and the patched plugin from https://github.com/JetBrains/resharper-unity/

 

In Addition to Put `-langversion:7.2` in mcs.rsp

I have wrote EditorExtension than do the job for VS

Put it to separate asmdef and enable for editor only

Code (CSharp):

1. using System;
2. using System.IO;
3. using System.Text;
4. using SyntaxTree.VisualStudio.Unity.Bridge;
5. using UnityEditor;
6. using UnityEditor.Compilation;
7. using UnityEditorInternal;
8. using UnityEngine;
9.  
10. [InitializeOnLoad]
11. public class CsProjFixer
12. {
13.     static CsProjFixer()
14.     {
15.         ProjectFilesGenerator.ProjectFileGeneration += FixProj;
16.         //CompilationPipeline.assemblyCompilationStarted += a => Debug.Log( "[CsProjFixer] - FixProj: " + a );
17.     }
18.     private static String FixProj( String name, String content )
19.     {
20.         var path = CompilationPipeline.GetAssemblyDefinitionFilePathFromAssemblyName(name.Substring(0, name.Length-7));
21.        
22.         try
23.         {
24.             StringBuilder sb = new StringBuilder();
25.             string line = null;
26.  
27.             Boolean isEditor = name.Contains(".Editor");
28.            
29.             using (var sr = new StringReader(content))
30.             {
31.                 while ((line = sr.ReadLine()) != null)
32.                 {
33.                     if (line == "    <LangVersion>4</LangVersion>")
34.                     {
35.                         sb.AppendLine("    <LangVersion>6</LangVersion>");
36.                     }
37.                     else if (line == "    <LangVersion>6</LangVersion>")
38.                     {
39.                         sb.AppendLine("    <LangVersion>7.2</LangVersion>");
40.                     }
41.                     else if (line == "    <Reference Include=\"Boo.Lang\" />")
42.                     {
43.                     }
44.                     else if (line == "    <Reference Include=\"UnityScript.Lang\" />")
45.                     {
46.                     }
47.                     else if ( !String.IsNullOrEmpty(path) && line.StartsWith("    <None Include" ) )
48.                     {
49.  
50.                     }
51.                     else if (!isEditor)
52.                     {
53.                         if (line == "    <Reference Include=\"System.XML\" />")
54.                         {
55.                         }
56.                         else if (line == "    <Reference Include=\"System.Xml.Linq\" />")
57.                         {
58.                         }
59.                         else
60.                         {
61.                             sb.AppendLine(line);
62.                         }
63.                     }
64.                     else
65.                     {
66.                         sb.AppendLine(line);
67.                     }
68.                 }
69.             }
70.  
71.             return sb.ToString();
72.         }
73.         catch (Exception ex)
74.         {
75.             Debug.LogError        ( "[csProjFixer] - FixProj: Fix Fail for file: " + name );
76.             Debug.LogException    ( ex );
77.         }
78.  
79.         return content;
80.     }
81. }

 

Why not; it's well documented input format for MSBuild. Not worse than editing make-files.

 

Looking forward to c# 7 support so I can use binary literals. Keep up the good work!

 

https://bitbucket.org/alexzzzz/unity-c-5.0-and-6.0-integration/overview allows you to use C#7.2 elements that do not require an updated runtime. So binary literals will work for you.
We use it in our project, its great.