reflect new behavior as of 17.6

Author: TylerMSFT

docs/build/reference/zc-externconstexpr.md

@@ -1,10 +1,9 @@
 ---
 description: "Learn more about: `/Zc:externConstexpr` (Enable extern constexpr variables)"
 title: "/Zc:externConstexpr (Enable extern constexpr variables)"
-ms.date: "02/28/2018"
+ms.date: 10/12/2023
 f1_keywords: ["/Zc:externConstexpr"]
 helpviewer_keywords: ["-Zc:externConstexpr compiler option (C++)", "extern constexpr variables (C++)"]
-ms.assetid: 4da5e33a-2e4d-4ed2-8616-bd8f43265c27
 ---
 # `/Zc:externConstexpr` (Enable extern constexpr variables)
 
@@ -16,7 +15,11 @@ The **`/Zc:externConstexpr`** compiler option tells the compiler to conform to t
 
 ## Remarks
 
-The **`/Zc:externConstexpr`** compiler option causes the compiler to apply external linkage to variables declared by using `extern constexpr`. In earlier versions of Visual Studio, and by default or if **`/Zc:externConstexpr-`** is specified, Visual Studio applies internal linkage to **`constexpr`** variables even if the **`extern`** keyword is used. The **`/Zc:externConstexpr`** option is available starting in Visual Studio 2017 Update 15.6. and is off by default. The [`/permissive-`](permissive-standards-conformance.md) option does not enable **`/Zc:externConstexpr`**.
+The **`/Zc:externConstexpr`** compiler option causes the compiler to apply external linkage to variables declared by using `extern constexpr`.
+
+In earlier versions of Visual Studio, by default or if **`/Zc:externConstexpr-`** is specified, Visual Studio applies internal linkage to **`constexpr`** variables even if the **`extern`** keyword is used. The **`/Zc:externConstexpr`** option is available starting in Visual Studio 2017 Update 15.6. and is off by default.
+
+As of Visual Studio 2022 Update 17.6, the `/permissive-` option enables both `/Zc:lambda` and `/Zc:externConstexpr`. In prior versions, neither were enabled by `/permissive-`.
 
 If a header file contains a variable declared `extern constexpr`, it must be marked [`__declspec(selectany)`](../../cpp/selectany.md) in order to merge the duplicate declarations into a single instance in the linked binary. Otherwise you may see linker errors, for example, LNK2005, for violations of the one-definition rule.