add RequiresPreviewFeaturesAttribute

Author: SimonCropp

readme.md

@@ -342,6 +342,13 @@ struct UnscopedRefUsage
 <!-- endSnippet -->
 
 
+### RequiresPreviewFeaturesAttribute
+
+ * [RequiresPreviewFeatures](https://learn.microsoft.com/en-us/dotnet/api/system.runtime.versioning.requirespreviewfeaturesattribute)
+ * [Design](https://github.com/dotnet/designs/blob/main/accepted/2021/preview-features/preview-features.md)
+ * [API Proposal](https://github.com/dapr/dotnet-sdk/issues/1219)
+
+
 ### CallerArgumentExpressionAttribute
 
  * [CallerArgumentExpressionAttribute](https://learn.microsoft.com/en-us/dotnet/api/system.runtime.compilerservices.callerargumentexpressionattribute)

src/Consume/Consume.cs

@@ -525,4 +525,9 @@ public void Method(string x)
     public void Method(object x)
     {
     }
+
+    [RequiresPreviewFeatures("This method uses a preview feature.")]
+    public void UsePreviewFeature()
+    {
+    }
 }

src/Polyfill/RequiresPreviewFeaturesAttribute .cs

@@ -0,0 +1,61 @@
+// <auto-generated />
+#pragma warning disable
+
+#nullable enable
+
+#if !NET8_0_OR_GREATER
+
+namespace System.Runtime.Versioning;
+
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using Link = System.ComponentModel.DescriptionAttribute;
+
+[AttributeUsage(AttributeTargets.Assembly |
+                AttributeTargets.Module |
+                AttributeTargets.Class |
+                AttributeTargets.Interface |
+                AttributeTargets.Delegate |
+                AttributeTargets.Struct |
+                AttributeTargets.Enum |
+                AttributeTargets.Constructor |
+                AttributeTargets.Method |
+                AttributeTargets.Property |
+                AttributeTargets.Field |
+                AttributeTargets.Event,
+    Inherited = false)]
+[ExcludeFromCodeCoverage]
+[DebuggerNonUserCode]
+[Link("https://learn.microsoft.com/en-us/dotnet/api/system.runtime.versioning.requirespreviewfeaturesattribute")]
+#if PolyPublic
+public
+#endif
+sealed class RequiresPreviewFeaturesAttribute :
+    Attribute
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="RequiresPreviewFeaturesAttribute"/> class.
+    /// </summary>
+    public RequiresPreviewFeaturesAttribute()
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="RequiresPreviewFeaturesAttribute"/> class with the specified message.
+    /// </summary>
+    /// <param name="message">An optional message associated with this attribute instance.</param>
+    public RequiresPreviewFeaturesAttribute(string? message) =>
+        Message = message;
+
+    /// <summary>
+    /// Returns the optional message associated with this attribute instance.
+    /// </summary>
+    public string? Message { get; }
+
+    /// <summary>
+    /// Returns the optional URL associated with this attribute instance.
+    /// </summary>
+    public string? Url { get; set; }
+}
+
+#endif