[ci skip] style: upgrade projects to C# 11

NB: While using a higher C# version with lower framework version is possible, it's generally advised against because C# syntax may map to .NET types not available in older versions such as .NET Standard 2.1.

This change does not invite the codebase to upgrade to newer types, but rather take advantage of syntax sugar (such as file-scoped namespaces, when this project was updated to C# 10) that does not effect the compiled result.

However, this change does open up the possibilities to add extension methods for the "generic math" interfaces (made possible by static interface members), and these upcoming methods will be targeted to .NET 7 or greater **ONLY**.

CONTRIBUTING.md

@@ -5,7 +5,7 @@ or submit a pull request.
 
 ### Pull request guidelines
 
-This project uses C# 10.0 language features where feasible, and adheres to StyleCop rules with some minor adjustments.
+This project uses C# 11.0 language features where feasible, and adheres to StyleCop rules with some minor adjustments.
 There is an `.editorconfig` included in this repository. For quick and painless pull requests, ensure that the analyzer does not
 throw warnings.
 
@@ -13,7 +13,7 @@ throw warnings.
 
 Below are a few pointers to which you may refer, but keep in mind this is not an exhaustive list:
 
-- Use C# 10.0 features where possible
+- Use C# 11.0 features where possible
 - Try to ensure code is CLS-compliant. Where this is not possible, decorate methods with `CLSCompliantAttribute` and pass `false`
 - Follow all .NET guidelines and coding conventions.
   See https://docs.microsoft.com/en-us/dotnet/csharp/fundamentals/coding-style/coding-conventions

X10D.DSharpPlus/X10D.DSharpPlus.csproj

@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <TargetFrameworks>net7.0;net6.0;netstandard2.1</TargetFrameworks>
-        <LangVersion>10.0</LangVersion>
+        <LangVersion>11.0</LangVersion>
         <Optimize>true</Optimize>
         <ImplicitUsings>true</ImplicitUsings>
         <Authors>Oliver Booth</Authors>

X10D.Hosting/X10D.Hosting.csproj

@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <TargetFrameworks>net7.0;net6.0;netstandard2.1</TargetFrameworks>
-        <LangVersion>10.0</LangVersion>
+        <LangVersion>11.0</LangVersion>
         <Optimize>true</Optimize>
         <ImplicitUsings>true</ImplicitUsings>
         <Authors>Oliver Booth</Authors>

X10D.SourceGenerator/X10D.SourceGenerator.csproj

@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <TargetFramework>netstandard2.0</TargetFramework>
-        <LangVersion>10.0</LangVersion>
+        <LangVersion>11.0</LangVersion>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
     </PropertyGroup>

X10D.SourceValidator/X10D.SourceValidator.csproj

@@ -3,6 +3,7 @@
     <PropertyGroup>
         <OutputType>Exe</OutputType>
         <TargetFramework>net7.0</TargetFramework>
+        <LangVersion>11.0</LangVersion>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
     </PropertyGroup>

X10D.Tests/X10D.Tests.csproj

@@ -1,8 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFrameworks>net7.0;net6.0</TargetFrameworks>
-        <LangVersion>10.0</LangVersion>
+        <TargetFramework>net7.0</TargetFramework>
+        <LangVersion>11.0</LangVersion>
         <IsPackable>false</IsPackable>
         <Nullable>enable</Nullable>
         <ImplicitUsings>true</ImplicitUsings>

X10D.Unity/X10D.Unity.csproj

@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <TargetFramework>netstandard2.1</TargetFramework>
-        <LangVersion>10.0</LangVersion>
+        <LangVersion>11.0</LangVersion>
         <Optimize>true</Optimize>
         <ImplicitUsings>true</ImplicitUsings>
         <Authors>Oliver Booth</Authors>

X10D/X10D.csproj

@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <TargetFrameworks>net7.0;net6.0;netstandard2.1</TargetFrameworks>
-        <LangVersion>10.0</LangVersion>
+        <LangVersion>11.0</LangVersion>
         <Optimize>true</Optimize>
         <ImplicitUsings>true</ImplicitUsings>
         <Authors>Oliver Booth</Authors>