dotnet · BillWagner · May 14, 2024 · May 10, 2024 · May 10, 2024 · May 13, 2024
diff --git a/docs/ai/get-started-app-chat-template.md b/docs/ai/get-started-app-chat-template.md
@@ -1,7 +1,7 @@
 ---
 title: Get started with the .NET enterprise chat app sample using RAG 
 description: Get started with .NET and search across your own data using a chat app sample implemented using Azure OpenAI Service and Retrieval Augmented Generation (RAG) in Azure AI Search. Easily deploy with Azure Developer CLI. This article uses the Azure AI Reference Template sample.
-ms.date: 11/19/2023
+ms.date: 05/10/2024
 ms.topic: get-started
 ms.custom: devx-track-dotnet, devx-track-dotnet-ai
 # CustomerIntent: As a .NET developer new to Azure OpenAI, I want deploy and use sample code to interact with app infused with my own business data so that learn from the sample code.
@@ -13,9 +13,6 @@ This article shows you how to deploy and run the [Enterprise chat app sample for
 
 * [Demo video](https://aka.ms/azai/net/video)
 
-> [!div class="nextstepaction"]
-> [Begin now](#open-development-environment)
-
 By following the instructions in this article, you will:
 
 - Deploy a chat app to Azure.
@@ -181,7 +178,7 @@ The sample repository contains all the code and configuration files you need to
 The chat app is preloaded with employee benefits information from [PDF files](https://github.com/Azure-Samples/azure-search-openai-demo-csharp/tree/main/data). You can use the chat app to ask questions about the benefits. The following steps walk you through the process of using the chat app.
 
 1. In the browser, navigate to the **Chat** page using the left navigation.
-1. Select or enter "What is included in my Northwind Health Plus plan that is not in standard?" in the chat text box.
+1. Select or enter "What is included in my Northwind Health Plus plan that is not in standard?" in the chat text box. Your response is _similar_ to the following image.
 
     :::image type="content" source="./media/get-started-app-chat-template/browser-chat-initial-answer.png" lightbox="./media/get-started-app-chat-template/browser-chat-initial-answer.png" alt-text="Screenshot of chat app's first answer.":::
 
@@ -218,17 +215,13 @@ The intelligence of the chat is determined by the OpenAI model and the settings
 The following steps walk you through the process of changing the settings.
 
 1. In the browser, select the gear icon in the upper right of the page.
-1. Check the **Suggest follow-up questions** checkbox and ask the same question again.
+1. If not selected, select the **Suggest follow-up questions** checkbox and ask the same question again.
 
     ```Text
-    What is my deductible?
+   What is included in my Northwind Health Plus plan that is not in standard?
     ```
 
-    The chat returns follow-up question suggestions such as the following:
-
-    - "What is the cost sharing for out-of-network services?"
-    - "Are preventive care services subject to the deductible?"
-    - "How does the prescription drug deductible work?"
+    The chat might return with follow-up question suggestions.
 
 1. In the **Settings** tab, deselect **Use semantic ranker for retrieval**.
 1. Ask the same question again.
@@ -239,9 +232,7 @@ The following steps walk you through the process of changing the settings.
 
 1. What is the difference in the answers?
 
-    The response which used the Semantic ranker provided a single answer: `The deductible for the Northwind Health Plus plan is $2,000 per year`.
-
-    The response without semantic ranking returned a less direct answer: `Based on the information provided, it is unclear what your specific deductible is. The Northwind Health Plus plan has different deductible amounts for in-network and out-of-network services, and there is also a separate prescription drug deductible. I would recommend checking with your provider or referring to the specific benefits details for your plan to determine your deductible amount`.
+    The response that used the Semantic ranker provided a single answer. The response without semantic ranking returned a less direct answer.
 
 ## Clean up resources
 

diff --git a/docs/ai/media/get-started-app-chat-template/browser-chat-initial-answer.png b/docs/ai/media/get-started-app-chat-template/browser-chat-initial-answer.png
diff --git a/docs/ai/media/get-started-app-chat-template/browser-chat-with-your-data.png b/docs/ai/media/get-started-app-chat-template/browser-chat-with-your-data.png
diff --git a/docs/ai/media/get-started-app-chat-template/simple-architecture-diagram.png b/docs/ai/media/get-started-app-chat-template/simple-architecture-diagram.png
diff --git a/docs/azure/includes/dotnet-all.md b/docs/azure/includes/dotnet-all.md
diff --git a/docs/azure/includes/dotnet-new.md b/docs/azure/includes/dotnet-new.md
diff --git a/.../core/compatibility/core-libraries/9.0/obsolete-apis-with-custom-diagnostics.md b/.../core/compatibility/core-libraries/9.0/obsolete-apis-with-custom-diagnostics.md
@@ -2,7 +2,7 @@
 title: "Breaking change: .NET 9 obsoletions with custom IDs"
 titleSuffix: ""
 description: Learn about the .NET 9 breaking change in core .NET libraries where some APIs have been marked as obsolete with a custom diagnostic ID.
-ms.date: 04/05/2024
+ms.date: 05/09/2024
 ---
 # API obsoletions with non-default diagnostic IDs (.NET 9)
 
@@ -17,6 +17,8 @@ The following table lists the custom diagnostic IDs and their corresponding warn
 | Diagnostic ID | Description | Severity |
 | - | - |
 | [SYSLIB0009](../../../../fundamentals/syslib-diagnostics/syslib0009.md) | <xref:System.Net.AuthenticationManager> is not supported. Methods will no-op or throw <xref:System.PlatformNotSupportedException>. | Warning |
+| [SYSLIB0054](../../../../fundamentals/syslib-diagnostics/syslib0054.md) | <xref:System.Threading.Thread.VolatileRead%2A?displayProperty=nameWithType> and <xref:System.Threading.Thread.VolatileWrite%2A?displayProperty=nameWithType> are obsolete. Use <xref:System.Threading.Volatile.Read%2A?displayProperty=nameWithType> or <xref:System.Threading.Volatile.Write%2A?displayProperty=nameWithType> instead. | Warning |
+| [SYSLIB0055](../../../../fundamentals/syslib-diagnostics/syslib0055.md) | `AdvSimd.ShiftRightLogicalRoundedNarrowingSaturate*` methods with signed parameters are obsolete. Use the unsigned overloads instead. | Warning |
 
 ## Version introduced
 
@@ -38,6 +40,23 @@ These obsoletions can affect [source compatibility](../../categories.md#source-c
 
 - <xref:System.Net.AuthenticationManager?displayProperty=fullName>
 
+### SYSLIB0054
+
+- <xref:System.Threading.Thread.VolatileRead%2A?displayProperty=fullName>
+- <xref:System.Threading.Thread.VolatileWrite%2A?displayProperty=fullName>
+
+### SYSLIB0055
+
+- <xref:System.Runtime.Intrinsics.Arm.AdvSimd.Arm64.ShiftRightLogicalRoundedNarrowingSaturateScalar(System.Runtime.Intrinsics.Vector64{System.Int64},System.Byte)?displayProperty=fullName>
+- <xref:System.Runtime.Intrinsics.Arm.AdvSimd.Arm64.ShiftRightLogicalRoundedNarrowingSaturateScalar(System.Runtime.Intrinsics.Vector64{System.Int16},System.Byte)?displayProperty=fullName>
+- <xref:System.Runtime.Intrinsics.Arm.AdvSimd.Arm64.ShiftRightLogicalRoundedNarrowingSaturateScalar(System.Runtime.Intrinsics.Vector64{System.Int32},System.Byte)?displayProperty=fullName>
+- <xref:System.Runtime.Intrinsics.Arm.AdvSimd.ShiftRightLogicalRoundedNarrowingSaturateLower(System.Runtime.Intrinsics.Vector128{System.Int16},System.Byte)?displayProperty=fullName>
+- <xref:System.Runtime.Intrinsics.Arm.AdvSimd.ShiftRightLogicalRoundedNarrowingSaturateLower(System.Runtime.Intrinsics.Vector128{System.Int64},System.Byte)?displayProperty=fullName>
+- <xref:System.Runtime.Intrinsics.Arm.AdvSimd.ShiftRightLogicalRoundedNarrowingSaturateLower(System.Runtime.Intrinsics.Vector128{System.Int32},System.Byte)?displayProperty=fullName>
+- <xref:System.Runtime.Intrinsics.Arm.AdvSimd.ShiftRightLogicalRoundedNarrowingSaturateUpper(System.Runtime.Intrinsics.Vector64{System.SByte},System.Runtime.Intrinsics.Vector128{System.Int16},System.Byte)?displayProperty=fullName>
+- <xref:System.Runtime.Intrinsics.Arm.AdvSimd.ShiftRightLogicalRoundedNarrowingSaturateUpper(System.Runtime.Intrinsics.Vector64{System.Int16},System.Runtime.Intrinsics.Vector128{System.Int32},System.Byte)?displayProperty=fullName>
+- <xref:System.Runtime.Intrinsics.Arm.AdvSimd.ShiftRightLogicalRoundedNarrowingSaturateUpper(System.Runtime.Intrinsics.Vector64{System.Int32},System.Runtime.Intrinsics.Vector128{System.Int64},System.Byte)?displayProperty=fullName>
+
 ## See also
 
 - [API obsoletions with non-default diagnostic IDs (.NET 8)](../8.0/obsolete-apis-with-custom-diagnostics.md)

diff --git a/docs/core/testing/mstest-analyzers/mstest0025.md b/docs/core/testing/mstest-analyzers/mstest0025.md
@@ -0,0 +1,46 @@
+---
+title: "MSTEST0025: Use 'Assert.Fail' instead of an always-failing assert"
+description: "Learn about code analysis rule MSTEST0025: Use 'Assert.Fail' instead of an always-failing assert"
+ms.date: 05/07/2024
+f1_keywords:
+- MSTEST0025
+- PreferAssertFailOverAlwaysFalseConditionsAnalyzer
+helpviewer_keywords:
+- PreferAssertFailOverAlwaysFalseConditionsAnalyzer
+- MSTEST0025
+author: Evangelink
+ms.author: amauryleve
+---
+# MSTEST0025: Use 'Assert.Fail' instead of an always-failing assert
+
+| Property                            | Value                                                 |
+|-------------------------------------|-------------------------------------------------------|
+| **Rule ID**                         | MSTEST0025                                            |
+| **Title**                           | Use 'Assert.Fail' instead of an always-failing assert |
+| **Category**                        | Design                                                |
+| **Fix is breaking or non-breaking** | Non-breaking                                          |
+| **Enabled by default**              | Yes                                                   |
+| **Default severity**                | Info                                                  |
+| **Introduced in version**           | 3.4.0                                                 |
+
+## Cause
+
+This rule raises a diagnostic when a call to an assertion produces an always-false condition.
+
+## Rule description
+
+Using `Assert.Fail` over an always-failing assertion call provides clearer intent and better documentation for the code.
+
+When you encounter an assertion that always fails (for example, `Assert.IsTrue(false)`), it might not be immediately obvious to someone reading the code why the assertion is there or what condition it's trying to check. This can lead to confusion and wasted time for developers who come across the code later on.
+
+In contrast, using `Assert.Fail` allows you to provide a custom failure message, making it clear why the assertion is failing and what specific condition or scenario it's addressing. This message serves as documentation for the intent behind the assertion, helping other developers understand the purpose of the assertion without needing to dive deep into the code.
+
+Overall, using `Assert.Fail` promotes clarity, documentation, and maintainability in your codebase, making it a better choice over an always failing assertion call.
+
+## How to fix violations
+
+Ensure that calls to `Assert.IsTrue`, `Assert.IsFalse`, `Assert.AreEqual`, `Assert.AreNotEqual` or `Assert.IsNotNull` are not producing always-failing conditions.
+
+## When to suppress warnings
+
+We do not recommend suppressing warnings from this rule.
diff --git a/docs/csharp/language-reference/builtin-types/arrays.md b/docs/csharp/language-reference/builtin-types/arrays.md
@@ -41,6 +41,16 @@ The following example creates single-dimensional, multidimensional, and jagged a
 
 :::code language="csharp" source="./snippets/shared/Arrays.cs" id="DeclareArrays":::
 
+> [!IMPORTANT]
+> Many of the examples in this article use [collection expressions](../operators/collection-expressions.md) (which use square brackets) to initialize the arrays. Collection expressions were first introduced in C# 12, which shipped with .NET 8. If you can't ugrade to C# 12 yet, use `{` and `}` to initialize the arrays instead.
+>
+> ```csharp
+> // Collection expressions:
+> int[] array = [1, 2, 3, 4, 5, 6];
+> // Alternative syntax:
+> int[] array2 = {1, 2, 3, 4, 5, 6};
+> ```
+
 ## Single-dimensional arrays
 
 A *single-dimensional array* is a sequence of like elements. You access an element via its *index*. The *index* is its ordinal position in the sequence. The first element in the array is at index `0`. You create a single-dimensional array using the [new](../operators/new-operator.md) operator specifying the array element type and the number of elements. The following example declares and initializes single-dimensional arrays:

diff --git a/docs/csharp/language-reference/preprocessor-directives.md b/docs/csharp/language-reference/preprocessor-directives.md
@@ -88,12 +88,12 @@ The following code is compiled when `MYTEST` is **not** defined:
 
 You can use the operators [`==` (equality)](operators/equality-operators.md#equality-operator-) and [`!=` (inequality)](operators/equality-operators.md#inequality-operator-) to test for the [`bool`](builtin-types/bool.md) values `true` or `false`. `true` means the symbol is defined. The statement `#if DEBUG` has the same meaning as `#if (DEBUG == true)`. You can use the [`&&` (and)](operators/boolean-logical-operators.md#conditional-logical-and-operator-), [`||` (or)](operators/boolean-logical-operators.md#conditional-logical-or-operator-), and [`!` (not)](operators/boolean-logical-operators.md#logical-negation-operator-) operators to evaluate whether multiple symbols have been defined. You can also group symbols and operators with parentheses.
 
-The following is a complex directive that allows your code to take advantage of newer .NET features while remaining backward compatible.  For example, imagine that you're using a NuGet package in your code, but the package only supports .NET 6 and up, as well as .NET Standard 2.0 and up:
+The following is a complex directive that allows your code to take advantage of newer .NET features while remaining backward compatible. For example, imagine that you're using a NuGet package in your code, but the package only supports .NET 6 and up, as well as .NET Standard 2.0 and up:
 
 ```csharp
 #if (NET6_0_OR_GREATER || NETSTANDARD2_0_OR_GREATER)
     Console.WriteLine("Using .NET 6+ or .NET Standard 2+ code.");
-#elif
+#else
     Console.WriteLine("Using older code that doesn't support the above .NET versions.");
 #endif
 ```

diff --git a/...classes-and-structs/how-to-initialize-objects-by-using-an-object-initializer.md b/...classes-and-structs/how-to-initialize-objects-by-using-an-object-initializer.md
@@ -26,6 +26,10 @@ Object initializers can be used to set indexers in an object. The following exam
 
 [!code-csharp[InitializerIndexerExample](../../../../samples/snippets/csharp/programming-guide/classes-and-structs/object-collection-initializers/HowToIndexInitializer.cs#HowToIndexInitializer)]  
 
+The next example shows the order of execution of constructor and member initializations using constructor with and without parameter:
+
+[!code-csharp[ExecutionOrderExample](../../../../samples/snippets/csharp/programming-guide/classes-and-structs/object-collection-initializers/HowToIndexInitializer.cs#ObjectInitializersExecutionOrder)]  
+
 ## See also
 
 - [Object and Collection Initializers](object-and-collection-initializers.md)
diff --git a/docs/fsharp/language-reference/import-declarations-the-open-keyword.md b/docs/fsharp/language-reference/import-declarations-the-open-keyword.md
@@ -63,6 +63,31 @@ open type M.DU
 printfn "%A" A
 ```
 
+## Open from root path only with `global` specifier
+
+Nested modules like
+
+```fsharp
+module A =
+    module B =
+        ...
+```
+
+can be opened via
+
+```fsharp
+open A // opens A
+open B // opens A.B
+```
+
+To open **only** fully qualified modules or namespaces prefix them with the `global` specifier:
+
+```fsharp
+open global.A   // works
+open global.B   // this now fails
+open global.A.B // works
+```
+
 ## Namespaces That Are Open by Default
 
 Some namespaces are so frequently used in F# code that they are opened implicitly without the need of an explicit import declaration. The following table shows the namespaces that are open by default.

diff --git a/docs/fundamentals/networking/quic/quic-overview.md b/docs/fundamentals/networking/quic/quic-overview.md
@@ -314,7 +314,7 @@ The sample usage of `QuicStream` in client scenario:
 
 ```csharp
 // Consider connection from the connection example, open a bidirectional stream.
-await using var stream = await connection.OpenStreamAsync(QuicStreamType.Bidirectional, cancellationToken);
+await using var stream = await connection.OpenOutboundStreamAsync(QuicStreamType.Bidirectional, cancellationToken);
 
 // Send some data.
 await stream.WriteAsync(data, cancellationToken);
@@ -338,7 +338,7 @@ And the sample usage of `QuicStream` in server scenario:
 
 ```csharp
 // Consider connection from the connection example, accept a stream.
-await using var stream = await connection.AcceptStreamAsync(cancellationToken);
+await using var stream = await connection.AcceptInboundStreamAsync(cancellationToken);
 
 if (stream.Type != QuicStreamType.Bidirectional)
 {

diff --git a/docs/fundamentals/syslib-diagnostics/obsoletions-overview.md b/docs/fundamentals/syslib-diagnostics/obsoletions-overview.md
@@ -2,7 +2,7 @@
 title: Obsolete features in .NET 5+
 titleSuffix: ""
 description: Learn about APIs that are marked as obsolete in .NET 5 and later versions that produce SYSLIB compiler warnings.
-ms.date: 06/08/2023
+ms.date: 05/09/2024
 ---
 
 # Obsolete features in .NET 5+
@@ -74,6 +74,8 @@ The following table provides an index to the `SYSLIB0XXX` obsoletions in .NET 5+
 | [SYSLIB0051](syslib0051.md) | Warning | APIs that support obsolete formatter-based serialization are obsolete. They should not be called or extended by application code. |
 | [SYSLIB0052](syslib0052.md) | Warning | APIs that support obsolete mechanisms for Regex extensibility are obsolete. |
 | [SYSLIB0053](syslib0053.md) | Warning | <xref:System.Security.Cryptography.AesGcm> should indicate the required tag size for encryption and decryption. Use a constructor that accepts the tag size. |
+| [SYSLIB0054](syslib0054.md) | Warning | <xref:System.Threading.Thread.VolatileRead%2A?displayProperty=nameWithType> and <xref:System.Threading.Thread.VolatileWrite%2A?displayProperty=nameWithType> are obsolete. Use <xref:System.Threading.Volatile.Read%2A?displayProperty=nameWithType> or <xref:System.Threading.Volatile.Write%2A?displayProperty=nameWithType> instead. |
+| [SYSLIB0055](syslib0055.md) | Warning | `AdvSimd.ShiftRightLogicalRoundedNarrowingSaturate*` methods with signed parameters are obsolete. Use the unsigned overloads instead. |
 
 ## Suppress warnings
 

diff --git a/docs/fundamentals/syslib-diagnostics/syslib0048.md b/docs/fundamentals/syslib-diagnostics/syslib0048.md
@@ -1,11 +1,11 @@
 ---
-title: SYSLIB0048 warning - RSA.EncryptValue and DecryptValue are obsolete
+title: SYSLIB0048 warning - RSA.EncryptValue and RSA.DecryptValue are obsolete
 description: Learn about the obsoletion of the RSA.EncryptValue and RSA.DecryptValue methods that generates compile-time warning SYSLIB0048.
 ms.date: 04/08/2022
 f1_keywords:
   - syslib0048
 ---
-# SYSLIB0048: RSA.EncryptValue and DecryptValue are obsolete
+# SYSLIB0048: RSA.EncryptValue and RSA.DecryptValue are obsolete
 
 The following methods are obsolete, starting in .NET 8. Calling them in code generates warning `SYSLIB0048` at compile time.
 

diff --git a/docs/fundamentals/syslib-diagnostics/syslib0054.md b/docs/fundamentals/syslib-diagnostics/syslib0054.md
@@ -0,0 +1,48 @@
+---
+title: SYSLIB0054 warning - Thread.VolatileRead and Thread.VolatileWrite are obsolete
+description: Learn about the obsoletion of Thread.VolatileRead and Thread.VolatileWrite that generates compile-time warning SYSLIB0054.
+ms.date: 05/09/2024
+f1_keywords:
+  - syslib0054
+---
+# SYSLIB0054: Thread.VolatileRead and Thread.VolatileWrite are obsolete
+
+All overloads of the <xref:System.Threading.Thread.VolatileRead%2A?displayProperty=nameWithType> and <xref:System.Threading.Thread.VolatileWrite%2A?displayProperty=nameWithType> methods are obsolete, starting in .NET 9. Calling them in code generates warning `SYSLIB0054` at compile time.
+
+## Reason for obsoletion
+
+The .NET Framework implementation of the 64-bit overloads of the <xref:System.Threading.Thread.VolatileRead%2A?displayProperty=nameWithType> and <xref:System.Threading.Thread.VolatileWrite%2A?displayProperty=nameWithType> methods had incorrect atomicity. In .NET (Core), the implementation was changed to delegate to the <xref:System.Threading.Volatile.Read%2A?displayProperty=nameWithType> and <xref:System.Threading.Volatile.Write%2A?displayProperty=nameWithType>, respectively, which provide proper acquire/release semantics. In addition, the methods in the <xref:System.Threading.Thread> class don't include an overload that accepts a Boolean argument, whereas the <xref:System.Threading.Volatile> methods do. The methods were obsoleted to encourage use of the <xref:System.Threading.Volatile> methods.
+
+## Workaround
+
+Call <xref:System.Threading.Volatile.Read%2A?displayProperty=nameWithType> or <xref:System.Threading.Volatile.Write%2A?displayProperty=nameWithType> instead.
+
+## Suppress a warning
+
+If you must use the obsolete APIs, you can suppress the warning in code or in your project file.
+
+To suppress only a single violation, add preprocessor directives to your source file to disable and then re-enable the warning.
+
+```csharp
+// Disable the warning.
+#pragma warning disable SYSLIB0054
+
+// Code that uses obsolete API.
+// ...
+
+// Re-enable the warning.
+#pragma warning restore SYSLIB0054
+```
+
+To suppress all the `SYSLIB0054` warnings in your project, add a `<NoWarn>` property to your project file.
+
+```xml
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+   ...
+   <NoWarn>$(NoWarn);SYSLIB0054</NoWarn>
+  </PropertyGroup>
+</Project>
+```
+
+For more information, see [Suppress warnings](obsoletions-overview.md#suppress-warnings).