From 8ed6cfbbee74ec9e03f2558b9c36f61dd7d4dcfd Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Thu, 22 Jul 2021 18:49:57 +0100 Subject: [PATCH] libstdc++: Fix non-default constructors for hash containers [PR101583] When I added the new mixin to _Hashtable, I forgot to explicitly construct it in each non-default constructor. That means you can't use any constructors unless all three of the hash function, equality function, and allocator are all default constructible. libstdc++-v3/ChangeLog: PR libstdc++/101583 * include/bits/hashtable.h (_Hashtable): Replace mixin with _Enable_default_ctor. Construct it explicitly in all non-forwarding, non-defaulted constructors. * testsuite/23_containers/unordered_map/cons/default.cc: Check non-default constructors can be used. * testsuite/23_containers/unordered_set/cons/default.cc: Likewise. --- libstdc++-v3/include/bits/hashtable.h | 17 ++++++++++++----- .../23_containers/unordered_map/cons/default.cc | 15 +++++++++++++++ .../23_containers/unordered_set/cons/default.cc | 14 ++++++++++++++ 3 files changed, 41 insertions(+), 5 deletions(-) diff --git a/libstdc++-v3/include/bits/hashtable.h b/libstdc++-v3/include/bits/hashtable.h index adb5921..92516b8 100644 --- a/libstdc++-v3/include/bits/hashtable.h +++ b/libstdc++-v3/include/bits/hashtable.h @@ -54,11 +54,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // from any other potentially-overlapping subobjects of the hashtable. template using _Hashtable_enable_default_ctor - = _Enable_special_members<__and_, + = _Enable_default_constructor<__and_, is_default_constructible<_Hash>, is_default_constructible<_Allocator>>{}, - true, true, true, true, true, - __detail::_Hash_node_base>; + __detail::_Hash_node_base>; /** * Primary class template _Hashtable. @@ -228,6 +227,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>; + using __enable_default_ctor + = _Hashtable_enable_default_ctor<_Equal, _Hash, _Alloc>; public: typedef _Key key_type; @@ -484,7 +485,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _Hashtable(const _Hash& __h, const _Equal& __eq, const allocator_type& __a) : __hashtable_base(__h, __eq), - __hashtable_alloc(__node_alloc_type(__a)) + __hashtable_alloc(__node_alloc_type(__a)), + __enable_default_ctor(_Enable_default_constructor_tag{}) { } template @@ -551,7 +553,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION explicit _Hashtable(const allocator_type& __a) - : __hashtable_alloc(__node_alloc_type(__a)) + : __hashtable_alloc(__node_alloc_type(__a)), + __enable_default_ctor(_Enable_default_constructor_tag{}) { } template @@ -1435,6 +1438,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __rehash_base(__ht), __hashtable_alloc( __node_alloc_traits::_S_select_on_copy(__ht._M_node_allocator())), + __enable_default_ctor(__ht), _M_buckets(nullptr), _M_bucket_count(__ht._M_bucket_count), _M_element_count(__ht._M_element_count), @@ -1457,6 +1461,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __map_base(__ht), __rehash_base(__ht), __hashtable_alloc(std::move(__a)), + __enable_default_ctor(__ht), _M_buckets(__ht._M_buckets), _M_bucket_count(__ht._M_bucket_count), _M_before_begin(__ht._M_before_begin._M_nxt), @@ -1487,6 +1492,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __map_base(__ht), __rehash_base(__ht), __hashtable_alloc(__node_alloc_type(__a)), + __enable_default_ctor(__ht), _M_buckets(), _M_bucket_count(__ht._M_bucket_count), _M_element_count(__ht._M_element_count), @@ -1508,6 +1514,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __map_base(__ht), __rehash_base(__ht), __hashtable_alloc(std::move(__a)), + __enable_default_ctor(__ht), _M_buckets(nullptr), _M_bucket_count(__ht._M_bucket_count), _M_element_count(__ht._M_element_count), diff --git a/libstdc++-v3/testsuite/23_containers/unordered_map/cons/default.cc b/libstdc++-v3/testsuite/23_containers/unordered_map/cons/default.cc index e4f836f..d64d078 100644 --- a/libstdc++-v3/testsuite/23_containers/unordered_map/cons/default.cc +++ b/libstdc++-v3/testsuite/23_containers/unordered_map/cons/default.cc @@ -31,3 +31,18 @@ static_assert( ! std::is_default_constructible{}, "PR libstdc++/100863" ); struct Equal : std::equal_to { Equal(int) { } }; using Map3 = std::unordered_map, Equal>; static_assert( ! std::is_default_constructible{}, "PR libstdc++/100863" ); + +// PR libstdc++/101583 +// verify non-default ctors can still be used +using Map4 = std::unordered_map>>; +Hash h(1); +Equal eq(1); +Map4::allocator_type a(1); +Map4 m{1, h, eq, a}; +Map4 m2{m.begin(), m.end(), m.size(), h, eq, a}; +Map4 m3{{{1,1}, {2,2}, {3,3}}, 3, h, eq, a}; +Map4 m4{m}; +Map4 m5{m, a}; +Map4 m6{std::move(m)}; +Map4 m7{std::move(m6), a}; diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/cons/default.cc b/libstdc++-v3/testsuite/23_containers/unordered_set/cons/default.cc index 42fbf3d..41281d3 100644 --- a/libstdc++-v3/testsuite/23_containers/unordered_set/cons/default.cc +++ b/libstdc++-v3/testsuite/23_containers/unordered_set/cons/default.cc @@ -31,3 +31,17 @@ static_assert( ! std::is_default_constructible{}, "PR libstdc++/100863" ); struct Equal : std::equal_to { Equal(int) { } }; using Set3 = std::unordered_set, Equal>; static_assert( ! std::is_default_constructible{}, "PR libstdc++/100863" ); + +// PR libstdc++/101583 +// verify non-default ctors can still be used +using Set4 = std::unordered_set>; +Hash h(1); +Equal eq(1); +Set4::allocator_type a(1); +Set4 s{1, h, eq, a}; +Set4 s2{s.begin(), s.end(), s.size(), h, eq, a}; +Set4 s3{{1, 2, 3}, 3, h, eq, a}; +Set4 s4{s}; +Set4 s5{s, a}; +Set4 s6{std::move(s)}; +Set4 s7{std::move(s6), a}; -- 2.7.4