This is the mail archive of the
libstdc++@gcc.gnu.org
mailing list for the libstdc++ project.
Remove unordered containers iterators default initialization
- From: François Dumont <frs dot dumont at gmail dot com>
- To: "libstdc++ at gcc dot gnu dot org" <libstdc++ at gcc dot gnu dot org>, gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 25 Nov 2013 22:02:45 +0100
- Subject: Remove unordered containers iterators default initialization
- Authentication-results: sourceware.org; auth=none
Hi
Following N3644 discussion thread here is a patch proposal to
remove default zero-initialization of unordered containers iterator. I
also took the time to remove default zero-init of nodes _M_nxt pointer.
2013-11-25 François Dumont <fdumont@gcc.gnu.org>
* include/bits/hashtable_policy.h (_Hash_node_base): Default
default constructor.
(_Node_iterator): Likewise.
(_Node_const_iterator): Likewise.
* include/bits/hashtable.h: Adapt.
Tested under Linux x86_64.
Ok to commit ?
François
Index: include/bits/hashtable_policy.h
===================================================================
--- include/bits/hashtable_policy.h (revision 205288)
+++ include/bits/hashtable_policy.h (working copy)
@@ -230,7 +230,7 @@
{
_Hash_node_base* _M_nxt;
- _Hash_node_base() noexcept : _M_nxt() { }
+ _Hash_node_base() = default;
_Hash_node_base(_Hash_node_base* __next) noexcept : _M_nxt(__next) { }
};
@@ -306,6 +306,7 @@
__node_type* _M_cur;
+ _Node_iterator_base() = default;
_Node_iterator_base(__node_type* __p) noexcept
: _M_cur(__p) { }
@@ -348,8 +349,7 @@
using reference = typename std::conditional<__constant_iterators,
const _Value&, _Value&>::type;
- _Node_iterator() noexcept
- : __base_type(0) { }
+ _Node_iterator() = default;
explicit
_Node_iterator(__node_type* __p) noexcept
@@ -396,8 +396,7 @@
typedef const _Value* pointer;
typedef const _Value& reference;
- _Node_const_iterator() noexcept
- : __base_type(0) { }
+ _Node_const_iterator() = default;
explicit
_Node_const_iterator(__node_type* __p) noexcept
Index: include/bits/hashtable.h
===================================================================
--- include/bits/hashtable.h (revision 205288)
+++ include/bits/hashtable.h (working copy)
@@ -788,6 +788,7 @@
__map_base(),
__rehash_base(),
__hashtable_alloc(__node_alloc_type(__a)),
+ _M_before_begin(nullptr),
_M_element_count(0),
_M_rehash_policy()
{
@@ -811,6 +812,7 @@
__map_base(),
__rehash_base(),
__hashtable_alloc(__node_alloc_type(__a)),
+ _M_before_begin(nullptr),
_M_element_count(0),
_M_rehash_policy()
{
@@ -952,6 +954,7 @@
// _M_before_begin.
__node_type* __ht_n = __ht._M_begin();
__node_type* __this_n = __node_gen(__ht_n);
+ __this_n->_M_nxt = nullptr;
this->_M_copy_code(__this_n, __ht_n);
_M_before_begin._M_nxt = __this_n;
_M_buckets[_M_bucket_index(__this_n)] = &_M_before_begin;
@@ -961,6 +964,7 @@
for (__ht_n = __ht_n->_M_next(); __ht_n; __ht_n = __ht_n->_M_next())
{
__this_n = __node_gen(__ht_n);
+ __this_n->_M_nxt = nullptr;
__prev_n->_M_nxt = __this_n;
this->_M_copy_code(__this_n, __ht_n);
size_type __bkt = _M_bucket_index(__this_n);
@@ -1092,6 +1096,7 @@
__node_alloc_traits::_S_select_on_copy(__ht._M_node_allocator())),
_M_buckets(),
_M_bucket_count(__ht._M_bucket_count),
+ _M_before_begin(nullptr),
_M_element_count(__ht._M_element_count),
_M_rehash_policy(__ht._M_rehash_policy)
{
@@ -1137,6 +1142,7 @@
__hashtable_alloc(__node_alloc_type(__a)),
_M_buckets(),
_M_bucket_count(__ht._M_bucket_count),
+ _M_before_begin(nullptr),
_M_element_count(__ht._M_element_count),
_M_rehash_policy(__ht._M_rehash_policy)
{
@@ -1158,6 +1164,7 @@
__hashtable_alloc(__node_alloc_type(__a)),
_M_buckets(),
_M_bucket_count(__ht._M_bucket_count),
+ _M_before_begin(nullptr),
_M_element_count(__ht._M_element_count),
_M_rehash_policy(__ht._M_rehash_policy)
{