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. From-SVN: r217442
2014-11-12 19:41:36 +00:00 · 2014-11-12 19:41:36 +00:00 · d8af84e67b
parent 3e147937ea
commit d8af84e67b
6 changed files with 50 additions and 26 deletions
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@ -7,6 +7,16 @@
 	* testsuite/20_util/shared_ptr/cons/43820_neg.cc: Adjust dg-error.
 	* testsuite/20_util/shared_ptr/cons/void_neg.cc: Adjust dg-error.

+	* 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.
+
 2014-11-12  Jonathan Wakely  <jwakely@redhat.com>

 	PR c++/33911
--- 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)) { }

--- 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; }
--- 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)
 	  {
--- 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 }
--- 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 }
 }