C++17 requires these to be noexcept, and there's no reason not to do
it for earlier standard modes too.
* include/bits/shared_ptr_base.h (__shared_ptr::owner_before)
(__weak_ptr::owner_before, _Sp_owner_less::operator()): Add noexcept
specifiers as per LWG 2873 and LWG 2942.
* testsuite/20_util/owner_less/noexcept.cc: New.
* testsuite/20_util/shared_ptr/observers/owner_before.cc: Test
noexcept guarantees.
* testsuite/20_util/weak_ptr/observers/owner_before.cc: Likewise.
Tested powerpc64le-linux, committed to trunk.
commit 82f522e382dac837924af829a70c61dd3db0ea94
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Mon Jun 5 10:12:22 2017 +0100
Add noexcept to shared_ptr owner comparisons (LWG 2873)
* include/bits/shared_ptr_base.h (__shared_ptr::owner_before)
(__weak_ptr::owner_before, _Sp_owner_less::operator()): Add noexcept
specifiers as per LWG 2873 and LWG 2942.
* testsuite/20_util/owner_less/noexcept.cc: New.
* testsuite/20_util/shared_ptr/observers/owner_before.cc: Test
noexcept guarantees.
* testsuite/20_util/weak_ptr/observers/owner_before.cc: Likewise.
diff --git a/libstdc++-v3/include/bits/shared_ptr_base.h
b/libstdc++-v3/include/bits/shared_ptr_base.h
index b4a5edf..f0916d0 100644
--- a/libstdc++-v3/include/bits/shared_ptr_base.h
+++ b/libstdc++-v3/include/bits/shared_ptr_base.h
@@ -1309,12 +1309,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp1>
bool
- owner_before(__shared_ptr<_Tp1, _Lp> const& __rhs) const
+ owner_before(__shared_ptr<_Tp1, _Lp> const& __rhs) const noexcept
{ return _M_refcount._M_less(__rhs._M_refcount); }
template<typename _Tp1>
bool
- owner_before(__weak_ptr<_Tp1, _Lp> const& __rhs) const
+ owner_before(__weak_ptr<_Tp1, _Lp> const& __rhs) const noexcept
{ return _M_refcount._M_less(__rhs._M_refcount); }
protected:
@@ -1697,12 +1697,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp1>
bool
- owner_before(const __shared_ptr<_Tp1, _Lp>& __rhs) const
+ owner_before(const __shared_ptr<_Tp1, _Lp>& __rhs) const noexcept
{ return _M_refcount._M_less(__rhs._M_refcount); }
template<typename _Tp1>
bool
- owner_before(const __weak_ptr<_Tp1, _Lp>& __rhs) const
+ owner_before(const __weak_ptr<_Tp1, _Lp>& __rhs) const noexcept
{ return _M_refcount._M_less(__rhs._M_refcount); }
void
@@ -1747,15 +1747,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct _Sp_owner_less : public binary_function<_Tp, _Tp, bool>
{
bool
- operator()(const _Tp& __lhs, const _Tp& __rhs) const
+ operator()(const _Tp& __lhs, const _Tp& __rhs) const noexcept
{ return __lhs.owner_before(__rhs); }
bool
- operator()(const _Tp& __lhs, const _Tp1& __rhs) const
+ operator()(const _Tp& __lhs, const _Tp1& __rhs) const noexcept
{ return __lhs.owner_before(__rhs); }
bool
- operator()(const _Tp1& __lhs, const _Tp& __rhs) const
+ operator()(const _Tp1& __lhs, const _Tp& __rhs) const noexcept
{ return __lhs.owner_before(__rhs); }
};
@@ -1764,7 +1764,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
template<typename _Tp, typename _Up>
auto
- operator()(const _Tp& __lhs, const _Up& __rhs) const
+ operator()(const _Tp& __lhs, const _Up& __rhs) const noexcept
-> decltype(__lhs.owner_before(__rhs))
{ return __lhs.owner_before(__rhs); }
diff --git a/libstdc++-v3/testsuite/20_util/owner_less/noexcept.cc
b/libstdc++-v3/testsuite/20_util/owner_less/noexcept.cc
new file mode 100644
index 0000000..25c9afd
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/owner_less/noexcept.cc
@@ -0,0 +1,40 @@
+// Copyright (C) 2017 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do compile { target c++11 } }
+
+#include <memory>
+
+const std::shared_ptr<int> si;
+const std::weak_ptr<int> wi;
+const std::owner_less<std::shared_ptr<int>> osi;
+static_assert( noexcept(osi(si, si)), "" );
+static_assert( noexcept(osi(si, wi)), "" );
+static_assert( noexcept(osi(wi, si)), "" );
+const std::owner_less<std::weak_ptr<int>> owi;
+static_assert( noexcept(owi(wi, wi)), "" );
+static_assert( noexcept(owi(si, wi)), "" );
+static_assert( noexcept(owi(wi, si)), "" );
+const std::shared_ptr<long> sl;
+const std::weak_ptr<char> wc;
+const std::owner_less<void> ov;
+static_assert( noexcept(ov(si, si)), "" );
+static_assert( noexcept(ov(si, sl)), "" );
+static_assert( noexcept(ov(sl, si)), "" );
+static_assert( noexcept(ov(si, wc)), "" );
+static_assert( noexcept(ov(wc, si)), "" );
+static_assert( noexcept(ov(wc, wi)), "" );
diff --git
a/libstdc++-v3/testsuite/20_util/shared_ptr/observers/owner_before.cc
b/libstdc++-v3/testsuite/20_util/shared_ptr/observers/owner_before.cc
index a913f618..f7e53f1 100644
--- a/libstdc++-v3/testsuite/20_util/shared_ptr/observers/owner_before.cc
+++ b/libstdc++-v3/testsuite/20_util/shared_ptr/observers/owner_before.cc
@@ -67,6 +67,12 @@ test02()
VERIFY( !a1.owner_before(w1) && !w1.owner_before(a1) );
std::weak_ptr<A> w2(a2);
VERIFY( !b1.owner_before(w2) && !w2.owner_before(b1) );
+
+ static_assert( noexcept(a1.owner_before(a0)), "" );
+ static_assert( noexcept(a1.owner_before(b1)), "" );
+ static_assert( noexcept(b1.owner_before(a1)), "" );
+ static_assert( noexcept(a1.owner_before(w1)), "" );
+ static_assert( noexcept(b1.owner_before(w1)), "" );
}
// Aliasing
diff --git a/libstdc++-v3/testsuite/20_util/weak_ptr/observers/owner_before.cc
b/libstdc++-v3/testsuite/20_util/weak_ptr/observers/owner_before.cc
index c3a952f..45f84db 100644
--- a/libstdc++-v3/testsuite/20_util/weak_ptr/observers/owner_before.cc
+++ b/libstdc++-v3/testsuite/20_util/weak_ptr/observers/owner_before.cc
@@ -27,7 +27,7 @@ struct B { };
// 20.6.6.3.5 weak_ptr observers [util.smartptr.weak.obs]
-int
+void
test01()
{
// test empty weak_ptrs compare equivalent
@@ -38,11 +38,14 @@ test01()
std::shared_ptr<B> p3;
VERIFY( !p1.owner_before(p3) && !p3.owner_before(p1) );
- return 0;
+ static_assert( noexcept(p1.owner_before(p1)), "" );
+ static_assert( noexcept(p1.owner_before(p2)), "" );
+ static_assert( noexcept(p1.owner_before(p3)), "" );
+ static_assert( noexcept(p2.owner_before(p1)), "" );
}
-int
+void
test02()
{
std::shared_ptr<A> a0;
@@ -60,8 +63,6 @@ test02()
std::shared_ptr<B> b1(new B);
VERIFY( w1.owner_before(b1) || b1.owner_before(w1) );
-
- return 0;
}
int
