When given a type which can convert to any container-like type, the
C(const C&) copy constructor and C(const C::_Base&) converting
constructor are ambiguous. This change replaces the converting
constructor's parameter with a reference_wrapper-like type so that
calling that constructor requires an additional user-defined conversion.
This gives it a lower rank than the copy constructor, avoiding the
ambiguity.
While testing this change I discovered that __gnu_debug::forward_list
doesn't have a convering constructor from the std::forward_list base, so
this adds it.
We should probably consider whether the converting constructors should
be 'explicit' but I'm not changing that now.
libstdc++-v3/ChangeLog:
PR libstdc++/90102
* include/debug/deque (deque(const _Base&)): Replace parameter
with a struct that wraps a const _Base&.
* include/debug/forward_list (forward_list(_Base_ref)): New
constructor.
* include/debug/list (list(const _Base&)): Replace parameter
with a struct that wraps a const _Base&.
* include/debug/map.h (map(const _Base&)): Likewise.
* include/debug/multimap.h (multimap(const _Base&)): Likewise.
* include/debug/multiset.h (multiset(const _Base&)): Likewise.
* include/debug/set.h (set(const _Base&)): Likewise.
* include/debug/unordered_map (unordered_map(const _Base&))
(unordered_multimap(const _Base&)): Likewise.
* include/debug/unordered_set (unordered_set(const _Base&))
(unordered_multiset(const _Base&)): Likewise.
* testsuite/23_containers/vector/cons/destructible_debug_neg.cc:
Adjust dg-error line number.
* include/debug/vector (vector(const _Base&)): Likewise.
* testsuite/23_containers/deque/debug/90102.cc: New test.
* testsuite/23_containers/forward_list/debug/90102.cc: New test.
* testsuite/23_containers/list/debug/90102.cc: New test.
* testsuite/23_containers/map/debug/90102.cc: New test.
* testsuite/23_containers/multimap/debug/90102.cc: New test.
* testsuite/23_containers/multiset/debug/90102.cc: New test.
* testsuite/23_containers/set/debug/90102.cc: New test.
* testsuite/23_containers/unordered_map/debug/90102.cc: New test.
* testsuite/23_containers/unordered_multimap/debug/90102.cc: New test.
* testsuite/23_containers/unordered_multiset/debug/90102.cc: New test.
* testsuite/23_containers/unordered_set/debug/90102.cc: New test.
* testsuite/23_containers/vector/debug/90102.cc: New test.
Tested powerpc64le-linux, committed to master.
commit eca833b81289438ec5ae3ed4c77ffb49cfb65f34
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Tue Jun 2 18:13:08 2020 +0100
libstdc++: Make debug containers prefer copy ctor to base ctor (PR 90102)
When given a type which can convert to any container-like type, the
C(const C&) copy constructor and C(const C::_Base&) converting
constructor are ambiguous. This change replaces the converting
constructor's parameter with a reference_wrapper-like type so that
calling that constructor requires an additional user-defined conversion.
This gives it a lower rank than the copy constructor, avoiding the
ambiguity.
While testing this change I discovered that __gnu_debug::forward_list
doesn't have a convering constructor from the std::forward_list base, so
this adds it.
We should probably consider whether the converting constructors should
be 'explicit' but I'm not changing that now.
libstdc++-v3/ChangeLog:
PR libstdc++/90102
* include/debug/deque (deque(const _Base&)): Replace parameter
with a struct that wraps a const _Base&.
* include/debug/forward_list (forward_list(_Base_ref)): New
constructor.
* include/debug/list (list(const _Base&)): Replace parameter
with a struct that wraps a const _Base&.
* include/debug/map.h (map(const _Base&)): Likewise.
* include/debug/multimap.h (multimap(const _Base&)): Likewise.
* include/debug/multiset.h (multiset(const _Base&)): Likewise.
* include/debug/set.h (set(const _Base&)): Likewise.
* include/debug/unordered_map (unordered_map(const _Base&))
(unordered_multimap(const _Base&)): Likewise.
* include/debug/unordered_set (unordered_set(const _Base&))
(unordered_multiset(const _Base&)): Likewise.
* testsuite/23_containers/vector/cons/destructible_debug_neg.cc:
Adjust dg-error line number.
* include/debug/vector (vector(const _Base&)): Likewise.
* testsuite/23_containers/deque/debug/90102.cc: New test.
* testsuite/23_containers/forward_list/debug/90102.cc: New test.
* testsuite/23_containers/list/debug/90102.cc: New test.
* testsuite/23_containers/map/debug/90102.cc: New test.
* testsuite/23_containers/multimap/debug/90102.cc: New test.
* testsuite/23_containers/multiset/debug/90102.cc: New test.
* testsuite/23_containers/set/debug/90102.cc: New test.
* testsuite/23_containers/unordered_map/debug/90102.cc: New test.
* testsuite/23_containers/unordered_multimap/debug/90102.cc: New
test.
* testsuite/23_containers/unordered_multiset/debug/90102.cc: New
test.
* testsuite/23_containers/unordered_set/debug/90102.cc: New test.
* testsuite/23_containers/vector/debug/90102.cc: New test.
diff --git a/libstdc++-v3/include/debug/deque b/libstdc++-v3/include/debug/deque
index 4d525bfc0aa..2bb99023870 100644
--- a/libstdc++-v3/include/debug/deque
+++ b/libstdc++-v3/include/debug/deque
@@ -64,6 +64,16 @@ namespace __debug
template<typename _ItT, typename _SeqT, typename _CatT>
friend class ::__gnu_debug::_Safe_iterator;
+ // Reference wrapper for base class. Disambiguates deque(const _Base&)
+ // from copy constructor by requiring a user-defined conversion.
+ // See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
typedef typename _Base::reference reference;
typedef typename _Base::const_reference const_reference;
@@ -143,8 +153,8 @@ namespace __debug
__gnu_debug::__base(__last), __a)
{ }
- deque(const _Base& __x)
- : _Base(__x) { }
+ deque(_Base_ref __x)
+ : _Base(__x._M_ref) { }
#if __cplusplus < 201103L
deque&
diff --git a/libstdc++-v3/include/debug/forward_list
b/libstdc++-v3/include/debug/forward_list
index 2fd03e70499..fc6bf6359e9 100644
--- a/libstdc++-v3/include/debug/forward_list
+++ b/libstdc++-v3/include/debug/forward_list
@@ -201,6 +201,14 @@ namespace __debug
template<typename _ItT, typename _SeqT, typename _CatT>
friend class ::__gnu_debug::_Safe_iterator;
+ // Reference wrapper for base class. See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
typedef typename _Base::reference reference;
typedef typename _Base::const_reference const_reference;
@@ -265,6 +273,8 @@ namespace __debug
~forward_list() = default;
+ forward_list(_Base_ref __x) : _Base(__x._M_ref) { }
+
forward_list&
operator=(const forward_list&) = default;
diff --git a/libstdc++-v3/include/debug/list b/libstdc++-v3/include/debug/list
index 6dd85741f81..8f2a8cb0f01 100644
--- a/libstdc++-v3/include/debug/list
+++ b/libstdc++-v3/include/debug/list
@@ -65,6 +65,16 @@ namespace __debug
template<typename _ItT, typename _SeqT, typename _CatT>
friend class ::__gnu_debug::_Safe_iterator;
+ // Reference wrapper for base class. Disambiguates list(const _Base&)
+ // from copy constructor by requiring a user-defined conversion.
+ // See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
typedef typename _Base::reference reference;
typedef typename _Base::const_reference const_reference;
@@ -144,8 +154,8 @@ namespace __debug
__gnu_debug::__base(__last), __a)
{ }
- list(const _Base& __x)
- : _Base(__x) { }
+ list(_Base_ref __x)
+ : _Base(__x._M_ref) { }
#if __cplusplus < 201103L
list&
diff --git a/libstdc++-v3/include/debug/map.h b/libstdc++-v3/include/debug/map.h
index adbabf62915..03eb0cbe332 100644
--- a/libstdc++-v3/include/debug/map.h
+++ b/libstdc++-v3/include/debug/map.h
@@ -59,6 +59,16 @@ namespace __debug
template<typename _ItT, typename _SeqT, typename _CatT>
friend class ::__gnu_debug::_Safe_iterator;
+ // Reference wrapper for base class. Disambiguates map(const _Base&)
+ // from copy constructor by requiring a user-defined conversion.
+ // See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
// types:
typedef _Key key_type;
@@ -126,8 +136,8 @@ namespace __debug
~map() = default;
#endif
- map(const _Base& __x)
- : _Base(__x) { }
+ map(_Base_ref __x)
+ : _Base(__x._M_ref) { }
explicit map(const _Compare& __comp,
const _Allocator& __a = _Allocator())
diff --git a/libstdc++-v3/include/debug/multimap.h
b/libstdc++-v3/include/debug/multimap.h
index 6cba52d35dc..e8d420e2196 100644
--- a/libstdc++-v3/include/debug/multimap.h
+++ b/libstdc++-v3/include/debug/multimap.h
@@ -59,6 +59,16 @@ namespace __debug
template<typename _ItT, typename _SeqT, typename _CatT>
friend class ::__gnu_debug::_Safe_iterator;
+ // Reference wrapper for base class. Disambiguates multimap(const _Base&)
+ // from copy constructor by requiring a user-defined conversion.
+ // See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
// types:
typedef _Key key_type;
@@ -138,8 +148,8 @@ namespace __debug
__gnu_debug::__base(__last),
__comp, __a) { }
- multimap(const _Base& __x)
- : _Base(__x) { }
+ multimap(_Base_ref __x)
+ : _Base(__x._M_ref) { }
#if __cplusplus < 201103L
multimap&
diff --git a/libstdc++-v3/include/debug/multiset.h
b/libstdc++-v3/include/debug/multiset.h
index a2d5e717b34..152ebcd6870 100644
--- a/libstdc++-v3/include/debug/multiset.h
+++ b/libstdc++-v3/include/debug/multiset.h
@@ -58,6 +58,16 @@ namespace __debug
template<typename _ItT, typename _SeqT, typename _CatT>
friend class ::__gnu_debug::_Safe_iterator;
+ // Reference wrapper for base class. Disambiguates multiset(const _Base&)
+ // from copy constructor by requiring a user-defined conversion.
+ // See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
// types:
typedef _Key key_type;
@@ -138,8 +148,8 @@ namespace __debug
__gnu_debug::__base(__last),
__comp, __a) { }
- multiset(const _Base& __x)
- : _Base(__x) { }
+ multiset(_Base_ref __x)
+ : _Base(__x._M_ref) { }
#if __cplusplus < 201103L
multiset&
diff --git a/libstdc++-v3/include/debug/set.h b/libstdc++-v3/include/debug/set.h
index 210186623df..85bc89e9915 100644
--- a/libstdc++-v3/include/debug/set.h
+++ b/libstdc++-v3/include/debug/set.h
@@ -58,6 +58,16 @@ namespace __debug
template<typename _ItT, typename _SeqT, typename _CatT>
friend class ::__gnu_debug::_Safe_iterator;
+ // Reference wrapper for base class. Disambiguates set(const _Base&)
+ // from copy constructor by requiring a user-defined conversion.
+ // See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
// types:
typedef _Key key_type;
@@ -137,8 +147,8 @@ namespace __debug
__gnu_debug::__base(__last),
__comp, __a) { }
- set(const _Base& __x)
- : _Base(__x) { }
+ set(_Base_ref __x)
+ : _Base(__x._M_ref) { }
#if __cplusplus < 201103L
set&
diff --git a/libstdc++-v3/include/debug/unordered_map
b/libstdc++-v3/include/debug/unordered_map
index 17fbba3aade..7d55174f63b 100644
--- a/libstdc++-v3/include/debug/unordered_map
+++ b/libstdc++-v3/include/debug/unordered_map
@@ -81,6 +81,14 @@ namespace __debug
template<typename _ItT, typename _SeqT>
friend class ::__gnu_debug::_Safe_local_iterator;
+ // Reference wrapper for base class. See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
typedef typename _Base::size_type size_type;
typedef typename _Base::hasher hasher;
@@ -121,8 +129,8 @@ namespace __debug
unordered_map(const unordered_map&) = default;
- unordered_map(const _Base& __x)
- : _Base(__x) { }
+ unordered_map(_Base_ref __x)
+ : _Base(__x._M_ref) { }
unordered_map(unordered_map&&) = default;
@@ -776,6 +784,14 @@ namespace __debug
template<typename _ItT, typename _SeqT>
friend class ::__gnu_debug::_Safe_local_iterator;
+ // Reference wrapper for base class. See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
typedef typename _Base::size_type size_type;
typedef typename _Base::hasher hasher;
@@ -816,8 +832,8 @@ namespace __debug
unordered_multimap(const unordered_multimap&) = default;
- unordered_multimap(const _Base& __x)
- : _Base(__x) { }
+ unordered_multimap(_Base_ref __x)
+ : _Base(__x._M_ref) { }
unordered_multimap(unordered_multimap&&) = default;
diff --git a/libstdc++-v3/include/debug/unordered_set
b/libstdc++-v3/include/debug/unordered_set
index 4d30852186c..37031da947e 100644
--- a/libstdc++-v3/include/debug/unordered_set
+++ b/libstdc++-v3/include/debug/unordered_set
@@ -78,6 +78,14 @@ namespace __debug
template<typename _ItT, typename _SeqT>
friend class ::__gnu_debug::_Safe_local_iterator;
+ // Reference wrapper for base class. See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
typedef typename _Base::size_type size_type;
typedef typename _Base::hasher hasher;
@@ -118,8 +126,8 @@ namespace __debug
unordered_set(const unordered_set&) = default;
- unordered_set(const _Base& __x)
- : _Base(__x) { }
+ unordered_set(_Base_ref __x)
+ : _Base(__x._M_ref) { }
unordered_set(unordered_set&&) = default;
@@ -646,6 +654,14 @@ namespace __debug
template<typename _ItT, typename _SeqT>
friend class ::__gnu_debug::_Safe_local_iterator;
+ // Reference wrapper for base class. See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
typedef typename _Base::size_type size_type;
typedef typename _Base::hasher hasher;
@@ -686,8 +702,8 @@ namespace __debug
unordered_multiset(const unordered_multiset&) = default;
- unordered_multiset(const _Base& __x)
- : _Base(__x) { }
+ unordered_multiset(_Base_ref __x)
+ : _Base(__x._M_ref) { }
unordered_multiset(unordered_multiset&&) = default;
diff --git a/libstdc++-v3/include/debug/vector
b/libstdc++-v3/include/debug/vector
index 4c08ab61ce8..47466169f8e 100644
--- a/libstdc++-v3/include/debug/vector
+++ b/libstdc++-v3/include/debug/vector
@@ -135,6 +135,16 @@ namespace __debug
template<typename _ItT, typename _SeqT, typename _CatT>
friend class ::__gnu_debug::_Safe_iterator;
+ // Reference wrapper for base class. Disambiguates vector(const _Base&)
+ // from copy constructor by requiring a user-defined conversion.
+ // See PR libstdc++/90102.
+ struct _Base_ref
+ {
+ _Base_ref(const _Base& __r) : _M_ref(__r) { }
+
+ const _Base& _M_ref;
+ };
+
public:
typedef typename _Base::reference reference;
typedef typename _Base::const_reference const_reference;
@@ -207,8 +217,8 @@ namespace __debug
: _Base(__x, __a) { }
vector(vector&& __x, const allocator_type& __a)
- noexcept( noexcept(
- _Base(std::declval<_Base&&>()), std::declval<const
allocator_type&>()) )
+ noexcept(noexcept(
+ _Base(std::declval<_Base&&>()), std::declval<const allocator_type&>()))
: _Safe(std::move(__x._M_safe()), __a),
_Base(std::move(__x._M_base()), __a),
_Safe_vector(std::move(__x)) { }
@@ -221,8 +231,8 @@ namespace __debug
#endif
/// Construction from a normal-mode vector
- vector(const _Base& __x)
- : _Base(__x) { }
+ vector(_Base_ref __x)
+ : _Base(__x._M_ref) { }
#if __cplusplus < 201103L
vector&
diff --git a/libstdc++-v3/testsuite/23_containers/deque/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/deque/debug/90102.cc
new file mode 100644
index 00000000000..80141a38ab8
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/deque/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/deque>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::deque<int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::deque<int> d(static_cast<std::deque<int>>(a));
diff --git a/libstdc++-v3/testsuite/23_containers/forward_list/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/forward_list/debug/90102.cc
new file mode 100644
index 00000000000..a382bde98a8
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/forward_list/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/forward_list>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::forward_list<int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::forward_list<int> d(static_cast<std::forward_list<int>>(a));
diff --git a/libstdc++-v3/testsuite/23_containers/list/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/list/debug/90102.cc
new file mode 100644
index 00000000000..49a23dc9d73
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/list/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/list>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::list<int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::list<int> d(static_cast<std::list<int>>(a));
diff --git a/libstdc++-v3/testsuite/23_containers/map/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/map/debug/90102.cc
new file mode 100644
index 00000000000..d50617f743a
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/map/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/map>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::map<int, int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::map<int, int> d(static_cast<std::map<int, int>>(a));
diff --git a/libstdc++-v3/testsuite/23_containers/multimap/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/multimap/debug/90102.cc
new file mode 100644
index 00000000000..f11e3fe332b
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/multimap/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/map>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::multimap<int, int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::multimap<int, int> d(static_cast<std::multimap<int, int>>(a));
diff --git a/libstdc++-v3/testsuite/23_containers/multiset/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/multiset/debug/90102.cc
new file mode 100644
index 00000000000..32ff73863c4
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/multiset/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/set>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::multiset<int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::multiset<int> d(static_cast<std::multiset<int>>(a));
diff --git a/libstdc++-v3/testsuite/23_containers/set/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/set/debug/90102.cc
new file mode 100644
index 00000000000..1da9f62bc81
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/set/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/set>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::set<int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::set<int> d(static_cast<std::set<int>>(a));
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_map/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/unordered_map/debug/90102.cc
new file mode 100644
index 00000000000..da7f3901e8b
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_map/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/unordered_map>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::unordered_map<int, int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::unordered_map<int, int> d(static_cast<std::unordered_map<int,
int>>(a));
diff --git
a/libstdc++-v3/testsuite/23_containers/unordered_multimap/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/unordered_multimap/debug/90102.cc
new file mode 100644
index 00000000000..398e7265491
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multimap/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/unordered_map>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::unordered_multimap<int, int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::unordered_multimap<int, int>
d(static_cast<std::unordered_multimap<int, int>>(a));
diff --git
a/libstdc++-v3/testsuite/23_containers/unordered_multiset/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/unordered_multiset/debug/90102.cc
new file mode 100644
index 00000000000..a257acf7d9d
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multiset/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/unordered_set>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::unordered_multiset<int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::unordered_multiset<int>
d(static_cast<std::unordered_multiset<int>>(a));
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/unordered_set/debug/90102.cc
new file mode 100644
index 00000000000..49f352f55d7
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_set/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/unordered_set>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::unordered_set<int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::unordered_set<int> d(static_cast<std::unordered_set<int>>(a));
diff --git
a/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
b/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
index 0eae8ee908c..9e58f0f4ddd 100644
--- a/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
+++ b/libstdc++-v3/testsuite/23_containers/vector/cons/destructible_debug_neg.cc
@@ -46,7 +46,7 @@ test02()
// { dg-error "value type is destructible" "" { target *-*-* } 0 }
// In Debug Mode the "required from here" errors come from <debug/vector>
-// { dg-error "required from here" "" { target *-*-* } 163 }
+// { dg-error "required from here" "" { target *-*-* } 173 }
// Needed because of PR c++/92193
// { dg-prune-output "deleted function" }
diff --git a/libstdc++-v3/testsuite/23_containers/vector/debug/90102.cc
b/libstdc++-v3/testsuite/23_containers/vector/debug/90102.cc
new file mode 100644
index 00000000000..19eb1fabafe
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/vector/debug/90102.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2020 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 <debug/vector>
+
+// PR libstdc++/90102
+
+struct AnyCont
+{
+ template<class Cont, class Check = decltype(std::declval<Cont>().clear())>
+ operator Cont () const;
+} a;
+
+// This should use copy constructor, not be ambiguous
+__gnu_debug::vector<int> c(a);
+
+// Ensure construction from base container still works
+__gnu_debug::vector<int> d(static_cast<std::vector<int>>(a));
