[clang] [libcxx] [SemaCXX] Implement CWG2137 (list-initialization from objects of the same type) (PR #77768)

[Mital Ashok via cfe-commits]

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@@ -132,6 +142,36 @@ namespace dr2126 { // dr2126: 12
 #endif
 }
 
+namespace dr2137 { // dr2137: 18
+#if __cplusplus >= 201103L
+  struct Q {
+    Q();
+    Q(Q&&);
+    Q(std::initializer_list<Q>) = delete; // since-cxx11-note 2 {{has been explicitly marked deleted here}}
+  };
+
+  Q x = Q { Q() }; // since-cxx11-error {{call to deleted constructor}}
+
+  int f(Q); // since-cxx11-note {{passing argument to parameter here}}
+  int y = f({ Q() }); // since-cxx11-error {{call to deleted constructor}}
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MitalAshok wrote:

@Endilll Is this good now? Thanks in advance

https://github.com/llvm/llvm-project/pull/77768/files#diff-3426b975672f064b9f32caf4ebab729b815f4f65aa3e76bda4b5bdee986e2e6fR130-R131

https://github.com/llvm/llvm-project/pull/77768/files#diff-8807231ab4d193692d6cecdc6428aaf3c55dfd96101cff8fe0eb7034654658fbR154-R161

https://github.com/llvm/llvm-project/pull/77768