add new warning for VS 17.6 - C5266

TylerMSFT · TylerMSFT · commit 5cbb6e34be39 · 2024-01-18T15:08:53.000-08:00
diff --git a/docs/error-messages/compiler-warnings/c5267.md b/docs/error-messages/compiler-warnings/c5267.md
@@ -11,11 +11,10 @@ helpviewer_keywords: ["C5267"]
 
 ## Remarks
 
-The C++ Standard deprecated (but didn't remove) the implicit generation of copy and assignment operators under some conditions. The MSVC compiler still generates the copy and assignment operators under those conditions, but may change its behavior in the future if the standard removes the deprecated behavior. The purpose of this warning is to help future proof your code if the committee decides to remove this functionality.
 
-The relevant sections in the C++ standard are:
-- [class.copy.ctor paragraph 6](https://eel.is/c++draft/class.copy.ctor#6), which says: "If the class definition does not explicitly declare a copy constructor, a nonexplicit one is declared implicitly. If the class definition declares a move constructor or move assignment operator, the implicitly declared copy constructor is defined as deleted; otherwise, it is defaulted. The latter case is deprecated if the class has a user-declared copy assignment operator or a user-declared destructor."
-- [Annex D D.8](https://eel.is/c++draft/depr.impldec#1), which says: "The implicit definition of a copy constructor as defaulted is deprecated if the class has a user-declared copy assignment operator or a user-declared destructor. The implicit definition of a copy assignment operator as defaulted is deprecated if the class has a user-declared copy constructor or a user-declared destructor. It's possible that future versions of C++ will specify that these implicit definitions are deleted."
+ 
+This warning is off by default.
+This warning was introduced in Visual Studio 17.6
 
 ## Example
 
diff --git a/docs/error-messages/compiler-warnings/compiler-warning-level-4-c5266.md b/docs/error-messages/compiler-warnings/compiler-warning-level-4-c5266.md
@@ -0,0 +1,34 @@
+---
+description: "Learn more about: Compiler Warning (level 4) C5266"
+title: "Compiler Warning (level 4) C5266"
+ms.date: 01/18/2024
+f1_keywords: ["C5266"]
+helpviewer_keywords: ["C5266"]
+---
+# Compiler Warning (level 4) C5266
+
+> 'const' qualifier on return type has no effect
+
+The C++ Standard specifies that a top-level const (or volatile) qualification on a function return type is ignored.
+
+This warning is off by default.\
+This warning was introduced in Visual Studio 17.6
+
+## Example
+
+The following sample generates C5266:
+
+```cpp
+// compile with: /W4 /c
+
+#pragma warning(default : 5266) // enable warning C5266 because it's off by default (or compile with /W45266)
+
+const int f() // warning C5266: 'const' qualifier on return type has no effect
+{
+    return 13;
+}
+```
+
+## See also
+
+[Enable warnings that are off by default](..\preprocessor\compiler-warnings-that-are-off-by-default.md)
diff --git a/docs/error-messages/compiler-warnings/compiler-warnings-by-compiler-version.md b/docs/error-messages/compiler-warnings/compiler-warnings-by-compiler-version.md
@@ -1,7 +1,7 @@
 ---
 title: "Compiler Warnings by compiler version"
 description: "Table of Microsoft C/C++ compiler warnings by compiler version."
-ms.date: 02/28/2023
+ms.date: 01/18/2024
 helpviewer_keywords: ["warnings, by compiler version", "cl.exe compiler, setting warning options"]
 ---
 # Compiler Warnings by compiler version
@@ -48,6 +48,7 @@ These versions of the compiler introduced new warnings:
 | Visual Studio 2022 version 17.3 | 19.33 |
 | Visual Studio 2022 version 17.4 | 19.34 |
 | Visual Studio 2022 version 17.5 | 19.35 |
+| Visual Studio 2022 version 17.6 | 19.36 |
 | Visual Studio 2022 version 17.7 | 19.37 |
 
 You can specify only the major number, the major and minor numbers, or the major, minor, and build numbers to the **`/Wv`** option. The compiler reports all warnings that match versions that begin with the specified number. It suppresses all warnings for versions greater than the specified number. For example, **`/Wv:17`** reports warnings introduced in or before any version of Visual Studio 2012, and suppresses warnings introduced by any compiler from Visual Studio 2013 (version 18) or later. To suppress warnings introduced in Visual Studio 2015 update 2 and later, you can use **`/Wv:19.00.23506`**. Use **`/Wv:19.11`** to report the warnings introduced in any version of Visual Studio before Visual Studio 2017 version 15.5, but suppress warnings introduced in Visual Studio 2017 version 15.5 and later.
@@ -64,6 +65,14 @@ These warnings, and all warnings in later versions, are suppressed by using the
 |--|--|
 | C5267 | definition of implicit copy constructor/assignment operator for '*type*' is deprecated because it has a user-provided assignment operator/copy constructor |
 
+## Warnings introduced in Visual Studio 2022 version 17.6 (compiler version 19.36)
+
+These warnings, and all warnings in later versions, are suppressed by using the compiler option **`/Wv:19.35`**.
+
+| Warning | Message |
+|--|--|
+| C5266 | 'const' qualifier on return type has no effect |
+
 ## Warnings introduced in Visual Studio 2022 version 17.5 (compiler version 19.35)
 
 These warnings, and all warnings in later versions, are suppressed by using the compiler option **`/Wv:19.34`**.
diff --git a/docs/error-messages/compiler-warnings/compiler-warnings-c4800-through-c4999.md b/docs/error-messages/compiler-warnings/compiler-warnings-c4800-through-c4999.md
@@ -1,9 +1,9 @@
 ---
 title: "Compiler warnings C4800 Through C5999"
 description: "Table of Microsoft C/C++ compiler warnings C4800 through C5999."
-ms.date: 03/01/2023
-f1_keywords: ["C4808", "C4809", "C4825", "C4827", "C4837", "C4842", "C4844", "C4845", "C4846", "C4847", "C4848", "C4854", "C4855", "C4856", "C4857", "C4872", "C4880", "C4881", "C4882", "C4916", "C4921", "C4934", "C4954", "C4955", "C4963", "C4966", "C4970", "C4971", "C4973", "C4974", "C4981", "C4983", "C4987", "C4988", "C4989", "C4990", "C4991", "C4992", "C4998", "C5022", "C5023", "C5024", "C5025", "C5026", "C5027", "C5028", "C5029", "C5030", "C5031", "C5032", "C5034", "C5035", "C5036", "C5039", "C5040", "C5041", "C5042", "C5043", "C5044", "C5047", "C5048", "C5049", "C5051", "C5052", "C5053", "C5057", "C5058", "C5059", "C5060", "C5061", "C5062", "C5063", "C5081", "C5100", "C5101", "C5102", "C5103", "C5104", "C5106", "C5107", "C5108", "C5200", "C5201", "C5202", "C5203", "C5204", "C5205", "C5206", "C5207", "C5209", "C5210", "C5211", "C5212", "C5213", "C5214", "C5215", "C5216", "C5217", "C5218", "C5219", "C5220", "C5221", "C5222", "C5223", "C5224", "C5225", "C5226", "C5227", "C5228", "C5229", "C5230", "C5231", "C5232", "C5233", "C5234", "C5235", "C5236", "C5237", "C5238", "C5239", "C5241", "C5242", "C5244", "C5245", "C5246", "C5249", "C5250", "C5251", "C5252", "C5253", "C5254", "C5255", "C5256", "C5257", "C5258", "C5259", "C5260", "C5261", "C5263", "C5264", "C5300"]
-helpviewer_keywords: ["C4808", "C4809", "C4825", "C4827", "C4837", "C4842", "C4844", "C4845", "C4846", "C4847", "C4848", "C4854", "C4855", "C4856", "C4857", "C4872", "C4880", "C4881", "C4882", "C4916", "C4921", "C4934", "C4954", "C4955", "C4963", "C4966", "C4970", "C4971", "C4973", "C4974", "C4981", "C4983", "C4987", "C4988", "C4989", "C4990", "C4991", "C4992", "C4998", "C5022", "C5023", "C5024", "C5025", "C5026", "C5027", "C5028", "C5029", "C5030", "C5031", "C5032", "C5034", "C5035", "C5036", "C5039", "C5040", "C5041", "C5042", "C5043", "C5044", "C5047", "C5048", "C5049", "C5051", "C5052", "C5053", "C5057", "C5058", "C5059", "C5060", "C5061", "C5062", "C5063", "C5081", "C5100", "C5101", "C5102", "C5103", "C5104", "C5106", "C5107", "C5108", "C5200", "C5201", "C5202", "C5203", "C5204", "C5205", "C5206", "C5207", "C5209", "C5210", "C5211", "C5212", "C5213", "C5214", "C5215", "C5216", "C5217", "C5218", "C5219", "C5220", "C5221", "C5222", "C5223", "C5224", "C5225", "C5226", "C5227", "C5228", "C5229", "C5230", "C5231", "C5232", "C5233", "C5234", "C5235", "C5236", "C5237", "C5238", "C5239", "C5241", "C5242", "C5244", "C5245", "C5246", "C5249", "C5250", "C5251", "C5252", "C5253", "C5254", "C5255", "C5256", "C5257", "C5258", "C5259", "C5260", "C5261", "C5263", "C5264", "C5300"]
+ms.date: 01/18/2024
+f1_keywords: ["C4808", "C4809", "C4825", "C4827", "C4837", "C4842", "C4844", "C4845", "C4846", "C4847", "C4848", "C4854", "C4855", "C4856", "C4857", "C4872", "C4880", "C4881", "C4882", "C4916", "C4921", "C4934", "C4954", "C4955", "C4963", "C4966", "C4970", "C4971", "C4973", "C4974", "C4981", "C4983", "C4987", "C4988", "C4989", "C4990", "C4991", "C4992", "C4998", "C5022", "C5023", "C5024", "C5025", "C5026", "C5027", "C5028", "C5029", "C5030", "C5031", "C5032", "C5034", "C5035", "C5036", "C5039", "C5040", "C5041", "C5042", "C5043", "C5044", "C5047", "C5048", "C5049", "C5051", "C5052", "C5053", "C5057", "C5058", "C5059", "C5060", "C5061", "C5062", "C5063", "C5081", "C5100", "C5101", "C5102", "C5103", "C5104", "C5106", "C5107", "C5108", "C5200", "C5201", "C5202", "C5203", "C5204", "C5205", "C5206", "C5207", "C5209", "C5210", "C5211", "C5212", "C5213", "C5214", "C5215", "C5216", "C5217", "C5218", "C5219", "C5220", "C5221", "C5222", "C5223", "C5224", "C5225", "C5226", "C5227", "C5228", "C5229", "C5230", "C5231", "C5232", "C5233", "C5234", "C5235", "C5236", "C5237", "C5238", "C5239", "C5241", "C5242", "C5244", "C5245", "C5246", "C5249", "C5250", "C5251", "C5252", "C5253", "C5254", "C5255", "C5256", "C5257", "C5258", "C5259", "C5260", "C5261", "C5263", "C5264", "C5266", "C5300"]
+helpviewer_keywords: ["C4808", "C4809", "C4825", "C4827", "C4837", "C4842", "C4844", "C4845", "C4846", "C4847", "C4848", "C4854", "C4855", "C4856", "C4857", "C4872", "C4880", "C4881", "C4882", "C4916", "C4921", "C4934", "C4954", "C4955", "C4963", "C4966", "C4970", "C4971", "C4973", "C4974", "C4981", "C4983", "C4987", "C4988", "C4989", "C4990", "C4991", "C4992", "C4998", "C5022", "C5023", "C5024", "C5025", "C5026", "C5027", "C5028", "C5029", "C5030", "C5031", "C5032", "C5034", "C5035", "C5036", "C5039", "C5040", "C5041", "C5042", "C5043", "C5044", "C5047", "C5048", "C5049", "C5051", "C5052", "C5053", "C5057", "C5058", "C5059", "C5060", "C5061", "C5062", "C5063", "C5081", "C5100", "C5101", "C5102", "C5103", "C5104", "C5106", "C5107", "C5108", "C5200", "C5201", "C5202", "C5203", "C5204", "C5205", "C5206", "C5207", "C5209", "C5210", "C5211", "C5212", "C5213", "C5214", "C5215", "C5216", "C5217", "C5218", "C5219", "C5220", "C5221", "C5222", "C5223", "C5224", "C5225", "C5226", "C5227", "C5228", "C5229", "C5230", "C5231", "C5232", "C5233", "C5234", "C5235", "C5236", "C5237", "C5238", "C5239", "C5241", "C5242", "C5244", "C5245", "C5246", "C5249", "C5250", "C5251", "C5252", "C5253", "C5254", "C5255", "C5256", "C5257", "C5258", "C5259", "C5260", "C5261", "C5263", "C5264", "C5266", "C5300"]
 ---
 # Compiler warnings C4800 through C5999
 
@@ -247,6 +247,7 @@ The articles in this section of the documentation explain a subset of the warnin
 | [Compiler warning (level 1, error, off) C5262](c5262.md) | implicit fall-through occurs here; are you missing a break statement? Use `[[fallthrough]]` when a `break` statement is intentionally omitted between cases |
 | Compiler warning (level 4, off) C5263 | calling '`std::move`' on a temporary object prevents copy elision |
 | Compiler warning (level 4, off) C5264 | '*variable-name*': 'const' variable is not used |
+| [Compiler warning (level 4, off) C5266](compiler-warning-level-4-c5266.md) | 'const' qualifier on return type has no effect |
 | [Compiler warning C5267](c5267.md) | definition of implicit copy constructor/assignment operator for '*type*' is deprecated because it has a user-provided assignment operator/copy constructor |
 | Compiler warning (level 1, error) C5300 | '#pragma omp atomic': left operand of '*operator*' must match left hand side of assignment-expression |
 | [Compiler warning (level 1) C5301](c5301-c5302.md) | '#pragma omp for': '*loop-index*' increases while loop condition uses '*comparison*'; non-terminating loop? |
diff --git a/docs/error-messages/toc.yml b/docs/error-messages/toc.yml
@@ -4363,6 +4363,8 @@ items:
           href: compiler-warnings/c5248.md
         - name: Compiler warning (level 1, error, off) C5262
           href: compiler-warnings/c5262.md
+        - name: Compiler warning (level 4) C5266
+          href: compiler-warnings/compiler-warning-level-4-c5266.md
         - name: Compiler warning (level 4) C5267
           href: compiler-warnings/c5267.md
         - name: Compiler warning (level 1) C5301 and C5302
diff --git a/docs/preprocessor/compiler-warnings-that-are-off-by-default.md b/docs/preprocessor/compiler-warnings-that-are-off-by-default.md
@@ -1,7 +1,7 @@
 ---
 description: "Learn more about: Compiler warnings that are off by default"
 title: "Compiler warnings that are off by default"
-ms.date: 11/15/2023
+ms.date: 01/18/2024
 helpviewer_keywords: ["warnings, compiler", "cl.exe compiler, setting options"]
 ---
 # Compiler warnings that are off by default
@@ -190,6 +190,7 @@ The following warnings are turned off by default in Visual Studio 2022 and later
 | [C5262](../error-messages/compiler-warnings/c5262.md) (level 1, error) | implicit fall-through occurs here; are you missing a `break` statement? Use `[[fallthrough]]` when a `break` statement is intentionally omitted between cases <sup>17.4</sup> |
 | C5263 (level 4) | calling '`std::move`' on a temporary object prevents copy elision <sup>17.4</sup> |
 | C5264 (level 4) | '*variable-name*': 'const' variable is not used <sup>17.4</sup> |
+| C5266 (level 4) | 'const' qualifier on return type has no effect <sup>17.6</sup> |
 | [C5267](../error-messages/compiler-warnings/c5267.md) (level 4) | definition of implicit copy constructor/assignment operator for '*type*' is deprecated because it has a user-provided assignment operator/copy constructor <sup>17.7</sup> |
 
 <sup>14.1</sup> This warning is available starting in Visual Studio 2015 Update 1.\
