[libcxx-commits] [PATCH] D124516: [libc++] Implement `std::expected` P0323R12

[Eric Fiselier via Phabricator via libcxx-commits]

EricWF added inline comments.


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Comment at: libcxx/include/__expected/expected.h:927
+    } else {
+      return __x.has_value() || static_cast<bool>(__x.error() == __y.error());
+    }
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Oh god, we can compare error types for equality that don't produce a boolean output. That's terrifying. I assume that's what the standard wants, but that's terrifying. 


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Comment at: libcxx/include/__expected/expected.h:933
+  _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const expected& __x, const unexpected<_E2>& __y) {
+    return !__x.has_value() && static_cast<bool>(__x.error() == __y.error());
+  }
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You can avoid the function calls by touching the members directly. That'll save in non-optimized build size.


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Comment at: libcxx/include/__expected/expected.h:937
+private:
+  bool __has_val_;
+  union {
----------------
Reverse the order of these members please.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D124516/new/

https://reviews.llvm.org/D124516