Tested powerpc64le-linux, pushed to trunk. Needs backporting.
-- >8 --
When I changed std::thread and std::async to avoid unnecessary move
construction of temporaries, I introduced a regression where types with
an explicit copy constructor could not be passed to std::thread or
std::async. The fix is to add a constructor instead of using aggregate
initialization of an unnamed temporary.
libstdc++-v3/ChangeLog:
PR libstdc++/106695
* include/bits/std_thread.h (thread::_State_impl): Forward
individual arguments to _Invoker constructor.
(thread::_Invoker): Add constructor. Delete copies.
* include/std/future (__future_base::_Deferred_state): Forward
individual arguments to _Invoker constructor.
(__future_base::_Async_state_impl): Likewise.
* testsuite/30_threads/async/106695.cc: New test.
* testsuite/30_threads/thread/106695.cc: New test.
---
libstdc++-v3/include/bits/std_thread.h | 8 ++++-
libstdc++-v3/include/std/future | 4 +--
.../testsuite/30_threads/async/106695.cc | 29 +++++++++++++++++++
.../testsuite/30_threads/thread/106695.cc | 21 ++++++++++++++
4 files changed, 59 insertions(+), 3 deletions(-)
create mode 100644 libstdc++-v3/testsuite/30_threads/async/106695.cc
create mode 100644 libstdc++-v3/testsuite/30_threads/thread/106695.cc
diff --git a/libstdc++-v3/include/bits/std_thread.h
b/libstdc++-v3/include/bits/std_thread.h
index d7fc0123564..3a7db12c6ba 100644
--- a/libstdc++-v3/include/bits/std_thread.h
+++ b/libstdc++-v3/include/bits/std_thread.h
@@ -227,7 +227,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename... _Args>
_State_impl(_Args&&... __args)
- : _M_func{{std::forward<_Args>(__args)...}}
+ : _M_func(std::forward<_Args>(__args)...)
{ }
void
@@ -261,6 +261,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tuple>
struct _Invoker
{
+ template<typename... _Args>
+ explicit
+ _Invoker(_Args&&... __args)
+ : _M_t(std::forward<_Args>(__args)...)
+ { }
+
_Tuple _M_t;
template<typename>
diff --git a/libstdc++-v3/include/std/future b/libstdc++-v3/include/std/future
index a925d03d19c..ba1f28c6c75 100644
--- a/libstdc++-v3/include/std/future
+++ b/libstdc++-v3/include/std/future
@@ -1681,7 +1681,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
explicit
_Deferred_state(_Args&&... __args)
: _M_result(new _Result<_Res>()),
- _M_fn{{std::forward<_Args>(__args)...}}
+ _M_fn(std::forward<_Args>(__args)...)
{ }
private:
@@ -1748,7 +1748,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
explicit
_Async_state_impl(_Args&&... __args)
: _M_result(new _Result<_Res>()),
- _M_fn{{std::forward<_Args>(__args)...}}
+ _M_fn(std::forward<_Args>(__args)...)
{
_M_thread = std::thread{&_Async_state_impl::_M_run, this};
}
diff --git a/libstdc++-v3/testsuite/30_threads/async/106695.cc
b/libstdc++-v3/testsuite/30_threads/async/106695.cc
new file mode 100644
index 00000000000..74996342dc7
--- /dev/null
+++ b/libstdc++-v3/testsuite/30_threads/async/106695.cc
@@ -0,0 +1,29 @@
+// { dg-do compile { target c++11 } }
+// { dg-require-gthreads "" }
+
+// PR libstdc++/106695
+// Explicit copy constructor does not work for a parameter passed via
std::async
+
+#include <future>
+
+struct A {
+ A() = default;
+ explicit A(const A&) = default;
+};
+
+void func(const A&) { }
+
+void
+test_async()
+{
+ (void) std::async(std::launch::async, func, A{});
+ (void) std::async(std::launch::deferred, func, A{});
+ (void) std::async(func, A{});
+}
+
+void
+test_task()
+{
+ std::packaged_task<void(const A&)> task(func);
+ task(A{});
+}
diff --git a/libstdc++-v3/testsuite/30_threads/thread/106695.cc
b/libstdc++-v3/testsuite/30_threads/thread/106695.cc
new file mode 100644
index 00000000000..97e9e922d8e
--- /dev/null
+++ b/libstdc++-v3/testsuite/30_threads/thread/106695.cc
@@ -0,0 +1,21 @@
+// { dg-do compile { target c++11 } }
+// { dg-require-gthreads "" }
+
+// PR libstdc++/106695
+// Explicit copy constructor does not work for a parameter passed via
std::async
+
+#include <thread>
+
+struct A {
+ A() = default;
+ explicit A(const A&) = default;
+};
+
+void func(const A&) { }
+
+void
+test_thread()
+{
+ std::thread t(func, A{});
+ t.join();
+}
--
2.37.2
