Tested x86_64-lixnu. Pushed to trunk. I'll backport this too. -- >8 --
I think an alternative fix would be something like: _M_ptr = std::exchange(rhs._M_ptr, nullptr); _M_refcount = std::move(rhs._M_refcount); The standard's move-and-swap implementation generates smaller code at all levels except -O0 and -Og, so it seems simplest to just do what the standard says. libstdc++-v3/ChangeLog: PR libstdc++/108118 * include/bits/shared_ptr_base.h (weak_ptr::operator=): Implement as move-and-swap exactly as specified in the standard. * testsuite/20_util/weak_ptr/cons/self_move.cc: New test. --- libstdc++-v3/include/bits/shared_ptr_base.h | 4 +--- .../20_util/weak_ptr/cons/self_move.cc | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+), 3 deletions(-) create mode 100644 libstdc++-v3/testsuite/20_util/weak_ptr/cons/self_move.cc diff --git a/libstdc++-v3/include/bits/shared_ptr_base.h b/libstdc++-v3/include/bits/shared_ptr_base.h index d9230b72203..c22b397a194 100644 --- a/libstdc++-v3/include/bits/shared_ptr_base.h +++ b/libstdc++-v3/include/bits/shared_ptr_base.h @@ -2049,9 +2049,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __weak_ptr& operator=(__weak_ptr&& __r) noexcept { - _M_ptr = __r._M_ptr; - _M_refcount = std::move(__r._M_refcount); - __r._M_ptr = nullptr; + __weak_ptr(std::move(__r)).swap(*this); return *this; } diff --git a/libstdc++-v3/testsuite/20_util/weak_ptr/cons/self_move.cc b/libstdc++-v3/testsuite/20_util/weak_ptr/cons/self_move.cc new file mode 100644 index 00000000000..c890d2ba94d --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/weak_ptr/cons/self_move.cc @@ -0,0 +1,19 @@ +// { dg-do run { target c++11 } } + +#include <memory> +#include <testsuite_hooks.h> + +void +test_self_move() +{ + std::shared_ptr<int> sp(new int(66)); + std::weak_ptr<int> wp(sp); + wp = std::move(wp); // PR libstdc++/108118 + std::shared_ptr<int> sp2(wp); + VERIFY(sp2 == sp); +} + +int main() +{ + test_self_move(); +} -- 2.38.1