This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[patch] Apply LWG 2399, 2400 and 2401 to std::shared_ptr and std::function
- From: Jonathan Wakely <jwakely at redhat dot com>
- To: libstdc++ at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org
- Date: Wed, 12 Nov 2014 19:47:42 +0000
- Subject: [patch] Apply LWG 2399, 2400 and 2401 to std::shared_ptr and std::function
- Authentication-results: sourceware.org; auth=none
These issues just became DRs in Urbana.
Tested x86_64-linux, committed to trunk.
The other new DRs we need to make changes for are 2212 (to shuffle
some code between headers), 2217 (which I sent an email about earlier)
and 2354 (adding some new insert overloads in RB trees).
commit 5930336c20503e26ed22f8ab5fe81146b31a60e5
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed Nov 12 14:21:41 2014 +0000
Implement resolutions of LWG 2399, 2400 and 2401.
* include/bits/shared_ptr.h (shared_ptr, weak_ptr): Define
_Convertible alias template to simplify constraints.
(shared_ptr(unique_ptr<TD>&&)): Constrain (LWG 2399).
* include/bits/shared_ptr_base.h: Likewise.
(_Sp_counted_deleter::_M_get_deleter()): Use addressof (LWG 2400).
* include/std/functional (function::operator=(nullptr_t)): Add
noexcept (LWG 2401).
* testsuite/20_util/shared_ptr/cons/43820_neg.cc: Adjust dg-error.
* testsuite/20_util/shared_ptr/cons/void_neg.cc: Adjust dg-error.
diff --git a/libstdc++-v3/include/bits/shared_ptr.h b/libstdc++-v3/include/bits/shared_ptr.h
index c2d56eb..22cb58a 100644
--- a/libstdc++-v3/include/bits/shared_ptr.h
+++ b/libstdc++-v3/include/bits/shared_ptr.h
@@ -92,6 +92,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
class shared_ptr : public __shared_ptr<_Tp>
{
+ template<typename _Ptr>
+ using _Convertible
+ = typename enable_if<is_convertible<_Ptr, _Tp*>::value>::type;
+
public:
/**
* @brief Construct an empty %shared_ptr.
@@ -213,8 +217,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @param __r A %shared_ptr.
* @post get() == __r.get() && use_count() == __r.use_count()
*/
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
shared_ptr(const shared_ptr<_Tp1>& __r) noexcept
: __shared_ptr<_Tp>(__r) { }
@@ -231,8 +234,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @param __r A %shared_ptr rvalue.
* @post *this contains the old value of @a __r, @a __r is empty.
*/
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
shared_ptr(shared_ptr<_Tp1>&& __r) noexcept
: __shared_ptr<_Tp>(std::move(__r)) { }
@@ -253,7 +255,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
shared_ptr(std::auto_ptr<_Tp1>&& __r);
#endif
- template<typename _Tp1, typename _Del>
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 2399. shared_ptr's constructor from unique_ptr should be constrained
+ template<typename _Tp1, typename _Del, typename
+ = _Convertible<typename unique_ptr<_Tp1, _Del>::pointer>>
shared_ptr(std::unique_ptr<_Tp1, _Del>&& __r)
: __shared_ptr<_Tp>(std::move(__r)) { }
@@ -464,25 +469,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
class weak_ptr : public __weak_ptr<_Tp>
{
+ template<typename _Ptr>
+ using _Convertible
+ = typename enable_if<is_convertible<_Ptr, _Tp*>::value>::type;
+
public:
constexpr weak_ptr() noexcept = default;
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
weak_ptr(const shared_ptr<_Tp1>& __r) noexcept
: __weak_ptr<_Tp>(__r) { }
weak_ptr(const weak_ptr&) noexcept = default;
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
weak_ptr(const weak_ptr<_Tp1>& __r) noexcept
: __weak_ptr<_Tp>(__r) { }
weak_ptr(weak_ptr&&) noexcept = default;
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
weak_ptr(weak_ptr<_Tp1>&& __r) noexcept
: __weak_ptr<_Tp>(std::move(__r)) { }
diff --git a/libstdc++-v3/include/bits/shared_ptr_base.h b/libstdc++-v3/include/bits/shared_ptr_base.h
index ea74000..fe397d0 100644
--- a/libstdc++-v3/include/bits/shared_ptr_base.h
+++ b/libstdc++-v3/include/bits/shared_ptr_base.h
@@ -477,7 +477,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_get_deleter(const std::type_info& __ti) noexcept
{
#ifdef __GXX_RTTI
- return __ti == typeid(_Deleter) ? &_M_impl._M_del() : nullptr;
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 2400. shared_ptr's get_deleter() should use addressof()
+ return __ti == typeid(_Deleter)
+ ? std::__addressof(_M_impl._M_del())
+ : nullptr;
#else
return nullptr;
#endif
@@ -862,6 +866,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp, _Lock_policy _Lp>
class __shared_ptr
{
+ template<typename _Ptr>
+ using _Convertible
+ = typename enable_if<is_convertible<_Ptr, _Tp*>::value>::type;
+
public:
typedef _Tp element_type;
@@ -916,8 +924,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__shared_ptr& operator=(const __shared_ptr&) noexcept = default;
~__shared_ptr() = default;
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
__shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
: _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount)
{ }
@@ -929,8 +936,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__r._M_ptr = 0;
}
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
__shared_ptr(__shared_ptr<_Tp1, _Lp>&& __r) noexcept
: _M_ptr(__r._M_ptr), _M_refcount()
{
@@ -950,7 +956,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
// If an exception is thrown this constructor has no effect.
- template<typename _Tp1, typename _Del>
+ template<typename _Tp1, typename _Del, typename
+ = _Convertible<typename unique_ptr<_Tp1, _Del>::pointer>>
__shared_ptr(std::unique_ptr<_Tp1, _Del>&& __r)
: _M_ptr(__r.get()), _M_refcount()
{
@@ -1331,6 +1338,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp, _Lock_policy _Lp>
class __weak_ptr
{
+ template<typename _Ptr>
+ using _Convertible
+ = typename enable_if<is_convertible<_Ptr, _Tp*>::value>::type;
+
public:
typedef _Tp element_type;
@@ -1356,14 +1367,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
//
// It is not possible to avoid spurious access violations since
// in multithreaded programs __r._M_ptr may be invalidated at any point.
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
__weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r) noexcept
: _M_refcount(__r._M_refcount)
{ _M_ptr = __r.lock().get(); }
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
__weak_ptr(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
: _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount)
{ }
@@ -1372,8 +1381,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: _M_ptr(__r._M_ptr), _M_refcount(std::move(__r._M_refcount))
{ __r._M_ptr = nullptr; }
- template<typename _Tp1, typename = typename
- std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ template<typename _Tp1, typename = _Convertible<_Tp1*>>
__weak_ptr(__weak_ptr<_Tp1, _Lp>&& __r) noexcept
: _M_ptr(__r.lock().get()), _M_refcount(std::move(__r._M_refcount))
{ __r._M_ptr = nullptr; }
diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index e711350..71d97ad 100644
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -2102,7 +2102,7 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
* The target of @c *this is deallocated, leaving it empty.
*/
function&
- operator=(nullptr_t)
+ operator=(nullptr_t) noexcept
{
if (_M_manager)
{
diff --git a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/43820_neg.cc b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/43820_neg.cc
index be33279..d354d20 100644
--- a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/43820_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/43820_neg.cc
@@ -32,7 +32,7 @@ void test01()
{
X* px = 0;
std::shared_ptr<X> p1(px); // { dg-error "here" }
- // { dg-error "incomplete" "" { target *-*-* } 878 }
+ // { dg-error "incomplete" "" { target *-*-* } 886 }
std::shared_ptr<X> p9(ap()); // { dg-error "here" }
// { dg-error "incomplete" "" { target *-*-* } 307 }
diff --git a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/void_neg.cc b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/void_neg.cc
index 17e036f..d833aea 100644
--- a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/void_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/void_neg.cc
@@ -25,5 +25,5 @@
void test01()
{
std::shared_ptr<void> p((void*)nullptr); // { dg-error "here" }
- // { dg-error "incomplete" "" { target *-*-* } 877 }
+ // { dg-error "incomplete" "" { target *-*-* } 885 }
}