feat: implement DisallowNothing method in Guard class

Author: gsscoder

CHANGELOG.md

@@ -7,7 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-- Updated .NET targets and dependencies
+- Updated .NET targets and dependencies.
+- Implemented `Guard::DisallowNothing` method.
 
 ## [6.4.6] - 2024-06-01
 

src/SharpX/Utilities/Guard.cs

@@ -79,4 +79,10 @@ public static void DisallowMalformedGuid(string argumentName, string value)
         try { Guid.Parse(value); }
         catch { throw new ArgumentException($"{argumentName} must be a well formed GUID.", argumentName); }
     }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static void DisallowNothing<T>(string argumentName, Maybe<T> value)
+    {
+        if (value.Tag == MaybeType.Nothing) throw new ArgumentException($"{argumentName} cannot be nothing.", argumentName);
+    }
 }