[libcxx-commits] [libcxx] [libc++] Ensure that `std::expected` has no tail padding (PR #69673)

[Louis Dionne via libcxx-commits]

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In-Reply-To: <llvm/llvm-project/pull/69673/libcxx at github.com>


================
@@ -119,31 +376,20 @@ class expected {
   _LIBCPP_HIDE_FROM_ABI constexpr expected()
     noexcept(is_nothrow_default_constructible_v<_Tp>) // strengthened
     requires is_default_constructible_v<_Tp>
-      : __has_val_(true) {
-    std::construct_at(std::addressof(__union_.__val_));
-  }
+      : __base(in_place) {}
 
   _LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&) = delete;
 
   _LIBCPP_HIDE_FROM_ABI constexpr expected(const expected&)
-    requires(is_copy_constructible_v<_Tp> &&
-             is_copy_constructible_v<_Err> &&
-             is_trivially_copy_constructible_v<_Tp> &&
-             is_trivially_copy_constructible_v<_Err>)
+    requires(is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Err> &&
----------------
ldionne wrote:

Let's not change `clang-format` for existing code in this patch if we can avoid it. It's already complicated enough like this!

https://github.com/llvm/llvm-project/pull/69673