[libcxx-commits] [libcxx] [libc++] Fix `tuple_cat` for element with unconstrained constructor (PR #122433)

[A. Jiang via libcxx-commits]

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@@ -31,6 +31,70 @@ template<typename ...Ts>
 void forward_as_tuple(Ts...) = delete;
 }
 
+// https://github.com/llvm/llvm-project/issues/41034
+struct Unconstrained {
+  int data;
+  template <typename Arg>
+  TEST_CONSTEXPR_CXX14 Unconstrained(Arg arg) : data(arg) {}
+};
+
+TEST_CONSTEXPR_CXX14 std::tuple<Unconstrained> test_cat_unary_lvalue() {
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frederick-vs-ja wrote:

Inlined.

https://github.com/llvm/llvm-project/pull/122433