[libcxx-commits] [PATCH] D156626: [libc++] Make the constraints as intended.

[khjj via Phabricator via libcxx-commits]

K1ZeKaTo updated this revision to Diff 546454.
K1ZeKaTo retitled this revision from "Make the constraints as intended." to "[libc++] Make the constraints as intended.".
K1ZeKaTo added a comment.

The constraints do not work while rvalue.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D156626/new/

https://reviews.llvm.org/D156626

Files:
  libcxx/include/__iterator/iter_move.h
  libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.move/iter_move.rvalue.verify.cpp


Index: libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.move/iter_move.rvalue.verify.cpp
===================================================================
--- /dev/null
+++ libcxx/test/std/iterators/iterator.requirements/iterator.cust/iterator.cust.move/iter_move.rvalue.verify.cpp
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// Test the constraints in libc++.
+
+// template<class I>
+// unspecified iter_move;
+
+#include <array>
+#include <utility>
+#include <iterator>
+
+template <typename I>
+class iterator_wrapper {
+public:
+  iterator_wrapper() = default;
+
+  constexpr explicit iterator_wrapper(I i) noexcept : base_(std::move(i)) {}
+
+  // This operator is used to check the constraints work.
+  constexpr auto&& operator*() && noexcept = delete;
+
+private:
+  I base_ = I{};
+};
+
+constexpr void test() {
+  std::array<int, 1> t1;
+  auto first = iterator_wrapper{std::move(t1)};
+
+  std::ranges::iter_move(std::move(first)); // expected-error and report as constraints not satisfied.
+}
Index: libcxx/include/__iterator/iter_move.h
===================================================================
--- libcxx/include/__iterator/iter_move.h
+++ libcxx/include/__iterator/iter_move.h
@@ -49,8 +49,8 @@
 concept __move_deref =
   !__unqualified_iter_move<_Tp> &&
   requires (_Tp&& __t) {
-    *__t;
-    requires is_lvalue_reference_v<decltype(*__t)>;
+    *std::forward<_Tp>(__t);
+    requires is_lvalue_reference_v<decltype(*std::forward<_Tp>(__t))>;
   };
 
 template<class _Tp>
@@ -58,8 +58,8 @@
   !__unqualified_iter_move<_Tp> &&
   !__move_deref<_Tp> &&
   requires (_Tp&& __t) {
-    *__t;
-    requires (!is_lvalue_reference_v<decltype(*__t)>);
+    *std::forward<_Tp>(__t);
+    requires (!is_lvalue_reference_v<decltype(*std::forward<_Tp>(__t))>);
   };
 
 // [iterator.cust.move]


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