[libcxx-commits] [PATCH] D69344: [libcxx] Add move constructor to compressed pair

[Zoe Carver via Phabricator via libcxx-commits]

zoecarver created this revision.
zoecarver added reviewers: ldionne, EricWF, mclow.lists.
Herald added subscribers: libcxx-commits, dexonsmith, christof.
Herald added a project: libc++.
zoecarver updated this revision to Diff 226153.
zoecarver added a comment.

- remove unnecessary template


This patch adds a move constructor to `__compressed_pair` so that move-only elements of nested compressed pairs (such as a move-only deleter in a `std::shared_ptr`) can be move-constructed.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D69344

Files:
  libcxx/include/memory
  libcxx/test/libcxx/utilities/compressed_pair/move_const.pass.cpp


Index: libcxx/test/libcxx/utilities/compressed_pair/move_const.pass.cpp
===================================================================
--- /dev/null
+++ libcxx/test/libcxx/utilities/compressed_pair/move_const.pass.cpp
@@ -0,0 +1,34 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// <memory>
+
+#include <memory>
+
+#include "test_macros.h"
+
+struct NoCopy {
+  NoCopy(NoCopy const&) = delete;
+  NoCopy() = delete;
+  explicit NoCopy(int) {}
+
+  NoCopy(NoCopy &&) = default;
+};
+
+template<class T>
+struct Foo {
+  std::__compressed_pair<std::__compressed_pair<NoCopy, int>, int> x;
+  Foo(T t, int i) : x(std::__compressed_pair<NoCopy, int>(std::move(t), i), 0) {}
+};
+
+int main(int, char**)
+{
+  Foo<NoCopy> f(NoCopy(0), 1);
+
+  return 0;
+}
\ No newline at end of file
Index: libcxx/include/memory
===================================================================
--- libcxx/include/memory
+++ libcxx/include/memory
@@ -2314,6 +2314,11 @@
       : _Base1(_VSTD::forward<_T1>(__t1)), _Base2(_VSTD::forward<_T2>(__t2)) {}
 #endif
 
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
+  __compressed_pair(__compressed_pair && __other)
+    : _Base1(_VSTD::move(__other.first())), _Base2(_VSTD::move(__other.second()))
+  {}
+
   _LIBCPP_INLINE_VISIBILITY
   typename _Base1::reference first() _NOEXCEPT {
     return static_cast<_Base1&>(*this).__get();


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