[clang] [Clang] Partial implementation of support for P3074 (trivial unions) (PR #146815)

[via cfe-commits]

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@@ -15,8 +16,9 @@ constexpr NonConstexpr2a nc2a = NonConstexpr2a(); // ok, does not call construct
 constexpr int nc2_a = NonConstexpr2().nl.a; // ok
 constexpr int nc2a_a = NonConstexpr2a().a; // ok
 struct Helper {
-  friend constexpr NonConstexpr1::NonConstexpr1(); // expected-error {{follows non-constexpr declaration}}
-  friend constexpr NonConstexpr2::NonConstexpr2(); // expected-error {{follows non-constexpr declaration}}
+  friend constexpr NonConstexpr1::NonConstexpr1(); // cxx11-23-error {{follows non-constexpr declaration}} cxx26-error {{missing exception specification}}
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Sirraide wrote:

That ‘is missing exception specification 'noexcept'’ error is weird; I’m also getting that before C++26 and only Clang errors on this; GCC, MSVC, and EDG seem to be fine with it. I don’t think that has anything to do w/ this patch but it’s still strange.

https://github.com/llvm/llvm-project/pull/146815