[clang] [Clang] Implement P0963R3 "Structured binding declaration as a condition" (PR #130228)

[via cfe-commits]

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@@ -529,8 +529,12 @@ def warn_cxx14_compat_decomp_decl : Warning<
 def ext_decomp_decl : ExtWarn<
   "decomposition declarations are a C++17 extension">, InGroup<CXX17>;
 def ext_decomp_decl_cond : ExtWarn<
-  "ISO C++17 does not permit structured binding declaration in a condition">,
-  InGroup<DiagGroup<"binding-in-condition">>;
+  "structured binding declaration in a condition is a C++2c extenstion">,
+  InGroup<CXX26>;
+def warn_cxx26_decomp_decl_cond : Warning<
+  "structured binding declaration in a condition is incompatible with "
+  "C++ standards before C++2c">,
+  InGroup<CXXPre26Compat>, DefaultIgnore;
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cor3ntin wrote:

I think we can remove Wbinding-in-condition, right ?

https://github.com/llvm/llvm-project/pull/130228