[flang] [clang] [libunwind] [compiler-rt] [libc] [libcxx] [clang-tools-extra] [lldb] [llvm] [libc++] Implement ranges::iota (PR #68494)

[James E T Smith via cfe-commits]

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@@ -1149,9 +1171,11 @@ struct Proxy {
   // Calling swap(Proxy<T>{}, Proxy<T>{}) would fail (pass prvalues)
 
   // Compare operators are defined for the convenience of the tests
-  friend constexpr bool operator==(const Proxy&, const Proxy&)
-    requires (std::equality_comparable<T> && !std::is_reference_v<T>)
-  = default;
+  friend constexpr bool operator==(const Proxy& lhs, const Proxy& rhs)
+    requires(std::equality_comparable<T> && !std::is_reference_v<T>)
+  {
+    return lhs.data == rhs.data;
+  };
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jamesETsmith wrote:

For this operator and the spaceship operator below, the default functions do not satisfy the requirements on the functions (e.g. `std::equality_comparable`) (see the previous discussion about it [here](https://github.com/llvm/llvm-project/pull/68494#issuecomment-1783604000)). 

https://github.com/llvm/llvm-project/pull/68494