[libcxx-commits] [libcxx] [libc++] Added `[[nodiscard]]` to `fstream.native_handle`, `span.at` and `in/out_ptr` (PR #167097)

[Nikolas Klauser via libcxx-commits]

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@@ -71,9 +71,11 @@ class out_ptr_t {
     }
   }
 
-  _LIBCPP_HIDE_FROM_ABI operator _Pointer*() const noexcept { return std::addressof(const_cast<_Pointer&>(__p_)); }
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI operator _Pointer*() const noexcept {
+    return std::addressof(const_cast<_Pointer&>(__p_));
+  }
 
-  _LIBCPP_HIDE_FROM_ABI operator void**() const noexcept
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI operator void**() const noexcept
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philnik777 wrote:

I don't think annotating the conversion operators makes a ton of sense. Nobody should ever call `ptr.operator void**()` and if you write `static_cast<void**>(ptr)` Clang will diagnose without the `[[nodiscard]]`.

https://github.com/llvm/llvm-project/pull/167097