https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96537
Bug ID: 96537
Summary: Missing std::pair constructor
Product: gcc
Version: 4.8.5
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: vries at gcc dot gnu.org
Target Milestone: ---
Consider test-case test.c:
...
#include <memory>
#include <unordered_map>
class A {
public:
A (int a) { i = a; }
int i;
};
int main (void) {
std::unordered_map<int, std::unique_ptr<A>> m;
m.emplace (1, new A(1));
return 0;
}
...
With gcc 7.5.0, we have:
...
$ g++-7 test.c -O2 -std=c++11
$ ./a.out
$
...
With gcc 4.8.5, we have instead:
...
$ g++-4.8 test.c -O2 -std=c++11
In file included from /usr/include/c++/4.8/bits/hashtable.h:35:0,
from /usr/include/c++/4.8/unordered_map:47,
from test.c:2:
/usr/include/c++/4.8/bits/hashtable_policy.h: In instantiation of
‘std::__detail::_Hash_node<_Value, false>::_Hash_node(_Args&& ...) [with _Args
= {int, A*}; _Value = std::pair<const int, std::unique_ptr<A> >]’:
/usr/include/c++/4.8/ext/new_allocator.h:120:4: required from ‘void
__gnu_cxx::new_allocator<_Tp>::construct(_Up*, _Args&& ...) [with _Up =
std::__detail::_Hash_node<std::pair<const int, std::unique_ptr<A> >, false>;
_Args = {int, A*}; _Tp = std::__detail::_Hash_node<std::pair<const int,
std::unique_ptr<A> >, false>]’
/usr/include/c++/4.8/bits/hashtable.h:727:6: required from
‘std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits>::__node_type* std::_Hashtable<_Key, _Value, _Alloc,
_ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy,
_Traits>::_M_allocate_node(_Args&& ...) [with _Args = {int, A*}; _Key = int;
_Value = std::pair<const int, std::unique_ptr<A> >; _Alloc =
std::allocator<std::pair<const int, std::unique_ptr<A> > >; _ExtractKey =
std::__detail::_Select1st; _Equal = std::equal_to<int>; _H1 = std::hash<int>;
_H2 = std::__detail::_Mod_range_hashing; _Hash =
std::__detail::_Default_ranged_hash; _RehashPolicy =
std::__detail::_Prime_rehash_policy; _Traits =
std::__detail::_Hashtable_traits<false, false, true>; std::_Hashtable<_Key,
_Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy,
_Traits>::__node_type = std::__detail::_Hash_node<std::pair<const int,
std::unique_ptr<A> >, false>]’
/usr/include/c++/4.8/bits/hashtable.h:1260:71: required from
‘std::pair<typename std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey,
_Equal, _H1, _H2, _Hash, _Traits>::iterator, bool> std::_Hashtable<_Key,
_Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy,
_Traits>::_M_emplace(std::true_type, _Args&& ...) [with _Args = {int, A*}; _Key
= int; _Value = std::pair<const int, std::unique_ptr<A> >; _Alloc =
std::allocator<std::pair<const int, std::unique_ptr<A> > >; _ExtractKey =
std::__detail::_Select1st; _Equal = std::equal_to<int>; _H1 = std::hash<int>;
_H2 = std::__detail::_Mod_range_hashing; _Hash =
std::__detail::_Default_ranged_hash; _RehashPolicy =
std::__detail::_Prime_rehash_policy; _Traits =
std::__detail::_Hashtable_traits<false, false, true>; typename
std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2,
_Hash, _Traits>::iterator = std::__detail::_Node_iterator<std::pair<const int,
std::unique_ptr<A> >, false, false>; std::true_type =
std::integral_constant<bool, true>]’
/usr/include/c++/4.8/bits/hashtable.h:665:69: required from
‘std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits>::__ireturn_type std::_Hashtable<_Key, _Value, _Alloc,
_ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::emplace(_Args&&
...) [with _Args = {int, A*}; _Key = int; _Value = std::pair<const int,
std::unique_ptr<A> >; _Alloc = std::allocator<std::pair<const int,
std::unique_ptr<A> > >; _ExtractKey = std::__detail::_Select1st; _Equal =
std::equal_to<int>; _H1 = std::hash<int>; _H2 =
std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash;
_RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits =
std::__detail::_Hashtable_traits<false, false, true>; std::_Hashtable<_Key,
_Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy,
_Traits>::__ireturn_type =
std::pair<std::__detail::_Node_iterator<std::pair<const int, std::unique_ptr<A>
>, false, false>, bool>]’
/usr/include/c++/4.8/bits/unordered_map.h:311:54: required from
‘std::pair<typename std::_Hashtable<_Key, std::pair<const _Key, _Tp>, _Alloc,
std::__detail::_Select1st, _Pred, _Hash, std::__detail::_Mod_range_hashing,
std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy,
std::__detail::_Hashtable_traits<std::__not_<std::__and_<std::__is_fast_hash<_Hash>,
std::is_default_constructible<_Hash>, std::is_copy_assignable<_Hash>,
std::__detail::__is_noexcept_hash<_Key, _Hash> > >::value, false, true>
>::iterator, bool> std::unordered_map<_Key, _Tp, _Hash, _Pred,
_Alloc>::emplace(_Args&& ...) [with _Args = {int, A*}; _Key = int; _Tp =
std::unique_ptr<A>; _Hash = std::hash<int>; _Pred = std::equal_to<int>; _Alloc
= std::allocator<std::pair<const int, std::unique_ptr<A> > >; typename
std::_Hashtable<_Key, std::pair<const _Key, _Tp>, _Alloc,
std::__detail::_Select1st, _Pred, _Hash, std::__detail::_Mod_range_hashing,
std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy,
std::__detail::_Hashtable_traits<std::__not_<std::__and_<std::__is_fast_hash<_Hash>,
std::is_default_constructible<_Hash>, std::is_copy_assignable<_Hash>,
std::__detail::__is_noexcept_hash<_Key, _Hash> > >::value, false, true>
>::iterator = std::__detail::_Node_iterator<std::pair<const int,
std::unique_ptr<A> >, false, false>]’
test.c:10:25: required from here
/usr/include/c++/4.8/bits/hashtable_policy.h:195:39: error: no matching
function for call to ‘std::pair<const int, std::unique_ptr<A> >::pair(int, A*)’
: _M_v(std::forward<_Args>(__args)...) { }
^
/usr/include/c++/4.8/bits/hashtable_policy.h:195:39: note: candidates are:
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:64:0,
from /usr/include/c++/4.8/memory:62,
from test.c:1:
/usr/include/c++/4.8/bits/stl_pair.h:206:9: note: template<class ... _Args1,
long unsigned int ..._Indexes1, class ... _Args2, long unsigned int
..._Indexes2> std::pair<_T1, _T2>::pair(std::tuple<_Args1 ...>&,
std::tuple<_Args2 ...>&, std::_Index_tuple<_Indexes1 ...>,
std::_Index_tuple<_Indexes2 ...>)
pair(tuple<_Args1...>&, tuple<_Args2...>&,
^
/usr/include/c++/4.8/bits/stl_pair.h:206:9: note: template argument
deduction/substitution failed:
In file included from /usr/include/c++/4.8/bits/hashtable.h:35:0,
from /usr/include/c++/4.8/unordered_map:47,
from test.c:2:
/usr/include/c++/4.8/bits/hashtable_policy.h:195:39: note: mismatched types
‘std::tuple<_Elements ...>’ and ‘int’
: _M_v(std::forward<_Args>(__args)...) { }
^
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:64:0,
from /usr/include/c++/4.8/memory:62,
from test.c:1:
/usr/include/c++/4.8/bits/stl_pair.h:155:9: note: template<class ... _Args1,
class ... _Args2> std::pair<_T1, _T2>::pair(std::piecewise_construct_t,
std::tuple<_Args1 ...>, std::tuple<_Args2 ...>)
pair(piecewise_construct_t, tuple<_Args1...>, tuple<_Args2...>);
^
/usr/include/c++/4.8/bits/stl_pair.h:155:9: note: template argument
deduction/substitution failed:
In file included from /usr/include/c++/4.8/bits/hashtable.h:35:0,
from /usr/include/c++/4.8/unordered_map:47,
from test.c:2:
/usr/include/c++/4.8/bits/hashtable_policy.h:195:39: note: cannot convert
‘std::forward<int>((* & __args#0))’ (type ‘int’) to type
‘std::piecewise_construct_t’
: _M_v(std::forward<_Args>(__args)...) { }
^
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:64:0,
from /usr/include/c++/4.8/memory:62,
from test.c:1:
/usr/include/c++/4.8/bits/stl_pair.h:150:12: note: template<class _U1, class
_U2, class> constexpr std::pair<_T1, _T2>::pair(std::pair<_U1, _U2>&&)
constexpr pair(pair<_U1, _U2>&& __p)
^
/usr/include/c++/4.8/bits/stl_pair.h:150:12: note: template argument
deduction/substitution failed:
In file included from /usr/include/c++/4.8/bits/hashtable.h:35:0,
from /usr/include/c++/4.8/unordered_map:47,
from test.c:2:
/usr/include/c++/4.8/bits/hashtable_policy.h:195:39: note: mismatched types
‘std::pair<_T1, _T2>’ and ‘int’
: _M_v(std::forward<_Args>(__args)...) { }
^
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:64:0,
from /usr/include/c++/4.8/memory:62,
from test.c:1:
/usr/include/c++/4.8/bits/stl_pair.h:144:12: note: template<class _U1, class
_U2, class> constexpr std::pair<_T1, _T2>::pair(_U1&&, _U2&&)
constexpr pair(_U1&& __x, _U2&& __y)
^
/usr/include/c++/4.8/bits/stl_pair.h:144:12: note: template argument
deduction/substitution failed:
/usr/include/c++/4.8/bits/stl_pair.h:141:38: error: no type named ‘type’ in
‘struct std::enable_if<false, void>’
template<class _U1, class _U2, class = typename
^
/usr/include/c++/4.8/bits/stl_pair.h:138:12: note: template<class _U2, class>
constexpr std::pair<_T1, _T2>::pair(const _T1&, _U2&&)
constexpr pair(const _T1& __x, _U2&& __y)
^
/usr/include/c++/4.8/bits/stl_pair.h:138:12: note: template argument
deduction/substitution failed:
/usr/include/c++/4.8/bits/stl_pair.h:136:27: error: no type named ‘type’ in
‘struct std::enable_if<false, void>’
template<class _U2, class = typename
^
/usr/include/c++/4.8/bits/stl_pair.h:133:12: note: template<class _U1, class>
constexpr std::pair<_T1, _T2>::pair(_U1&&, const _T2&)
constexpr pair(_U1&& __x, const _T2& __y)
^
/usr/include/c++/4.8/bits/stl_pair.h:133:12: note: template argument
deduction/substitution failed:
In file included from /usr/include/c++/4.8/bits/hashtable.h:35:0,
from /usr/include/c++/4.8/unordered_map:47,
from test.c:2:
/usr/include/c++/4.8/bits/hashtable_policy.h:195:39: note: cannot convert
‘std::forward<A*>((* & __args#1))’ (type ‘A*’) to type ‘const
std::unique_ptr<A>&’
: _M_v(std::forward<_Args>(__args)...) { }
^
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:64:0,
from /usr/include/c++/4.8/memory:62,
from test.c:1:
/usr/include/c++/4.8/bits/stl_pair.h:128:17: note: constexpr std::pair<_T1,
_T2>::pair(std::pair<_T1, _T2>&&) [with _T1 = const int; _T2 =
std::unique_ptr<A>]
constexpr pair(pair&&) = default;
^
/usr/include/c++/4.8/bits/stl_pair.h:128:17: note: candidate expects 1
argument, 2 provided
/usr/include/c++/4.8/bits/stl_pair.h:124:12: note: template<class _U1, class
_U2, class> constexpr std::pair<_T1, _T2>::pair(const std::pair<_U1, _U2>&)
constexpr pair(const pair<_U1, _U2>& __p)
^
/usr/include/c++/4.8/bits/stl_pair.h:124:12: note: template argument
deduction/substitution failed:
In file included from /usr/include/c++/4.8/bits/hashtable.h:35:0,
from /usr/include/c++/4.8/unordered_map:47,
from test.c:2:
/usr/include/c++/4.8/bits/hashtable_policy.h:195:39: note: mismatched types
‘const std::pair<_T1, _T2>’ and ‘int’
: _M_v(std::forward<_Args>(__args)...) { }
^
In file included from /usr/include/c++/4.8/bits/stl_algobase.h:64:0,
from /usr/include/c++/4.8/memory:62,
from test.c:1:
/usr/include/c++/4.8/bits/stl_pair.h:112:26: note: constexpr std::pair<_T1,
_T2>::pair(const _T1&, const _T2&) [with _T1 = const int; _T2 =
std::unique_ptr<A>]
_GLIBCXX_CONSTEXPR pair(const _T1& __a, const _T2& __b)
^
/usr/include/c++/4.8/bits/stl_pair.h:112:26: note: no known conversion for
argument 2 from ‘A*’ to ‘const std::unique_ptr<A>&’
/usr/include/c++/4.8/bits/stl_pair.h:108:26: note: constexpr std::pair<_T1,
_T2>::pair() [with _T1 = const int; _T2 = std::unique_ptr<A>]
_GLIBCXX_CONSTEXPR pair()
^
/usr/include/c++/4.8/bits/stl_pair.h:108:26: note: candidate expects 0
arguments, 2 provided
...
