diff --git a/doc/changes.qbk b/doc/changes.qbk
index 790e3863..adddc366 100644
--- a/doc/changes.qbk
+++ b/doc/changes.qbk
@@ -107,6 +107,10 @@ First official release.
* Support instantiating the containers with incomplete value types.
* Reduced the number of warnings (mostly in tests).
+* [@http://svn.boost.org/trac/boost/ticket/3693 Ticket 3693]:
+ Add `erase_return_void` as a temporary workaround for the current
+ `erase` which can be inefficient because it has to find the next
+ element to return an iterator.
* [@http://svn.boost.org/trac/boost/ticket/3773 Ticket 3773]:
Add missing `std` qualifier to `ptrdiff_t`.
diff --git a/doc/ref.xml b/doc/ref.xml
index 4ca51abf..b55b5492 100644
--- a/doc/ref.xml
+++ b/doc/ref.xml
@@ -459,6 +459,15 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Only throws an exception if it is thrown by hasher or key_equal.
In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+ When the number of elements is a lot smaller than the number of buckets
+ this function can be very inefficient as it has to search through empty
+ buckets for the next element, in order to return the iterator.
+ As a temporary workaround, the container has the method
+ erase_return_void which will be faster.
+
+
@@ -494,6 +503,27 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+ const_iterator
+
+ iterator
+
+ Erase the element pointed to by position.
+
+
+ Only throws an exception if it is thrown by hasher or key_equal.
+ In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+
+ This is a temporary workaround for the inefficient
+ erase method. Hopefully, in a future
+ version the signature of erase will
+ be changed and this will be deprecated.
+
+
+
void
@@ -1252,6 +1282,15 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Only throws an exception if it is thrown by hasher or key_equal.
In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+ When the number of elements is a lot smaller than the number of buckets
+ this function can be very inefficient as it has to search through empty
+ buckets for the next element, in order to return the iterator.
+ As a temporary workaround, the container has the method
+ erase_return_void which will be faster.
+
+
@@ -1287,6 +1326,27 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+ const_iterator
+
+ iterator
+
+ Erase the element pointed to by position.
+
+
+ Only throws an exception if it is thrown by hasher or key_equal.
+ In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+
+ This is a temporary workaround for the inefficient
+ erase method. Hopefully, in a future
+ version the signature of erase will
+ be changed and this will be deprecated.
+
+
+
void
@@ -2059,6 +2119,15 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Only throws an exception if it is thrown by hasher or key_equal.
In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+ When the number of elements is a lot smaller than the number of buckets
+ this function can be very inefficient as it has to search through empty
+ buckets for the next element, in order to return the iterator.
+ As a temporary workaround, the container has the method
+ erase_return_void which will be faster.
+
+
@@ -2094,6 +2163,27 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+ const_iterator
+
+ iterator
+
+ Erase the element pointed to by position.
+
+
+ Only throws an exception if it is thrown by hasher or key_equal.
+ In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+
+ This is a temporary workaround for the inefficient
+ erase method. Hopefully, in a future
+ version the signature of erase will
+ be changed and this will be deprecated.
+
+
+
void
@@ -2901,6 +2991,15 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Only throws an exception if it is thrown by hasher or key_equal.
In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+ When the number of elements is a lot smaller than the number of buckets
+ this function can be very inefficient as it has to search through empty
+ buckets for the next element, in order to return the iterator.
+ As a temporary workaround, the container has the method
+ erase_return_void which will be faster.
+
+
@@ -2936,6 +3035,27 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+ const_iterator
+
+ iterator
+
+ Erase the element pointed to by position.
+
+
+ Only throws an exception if it is thrown by hasher or key_equal.
+ In this implementation, this overload doesn't call either function object's methods so it is no throw, but this might not be true in other implementations.
+
+
+
+ This is a temporary workaround for the inefficient
+ erase method. Hopefully, in a future
+ version the signature of erase will
+ be changed and this will be deprecated.
+
+
+
void
diff --git a/include/boost/unordered/detail/fwd.hpp b/include/boost/unordered/detail/fwd.hpp
index ff3d63e9..7128dbe9 100644
--- a/include/boost/unordered/detail/fwd.hpp
+++ b/include/boost/unordered/detail/fwd.hpp
@@ -532,7 +532,8 @@ namespace boost { namespace unordered_detail {
void clear();
std::size_t erase_key(key_type const& k);
- iterator_base erase(iterator_base r);
+ iterator_base erase_return_iterator(iterator_base r);
+ void erase(iterator_base r);
std::size_t erase_group(node_ptr* it, bucket_ptr bucket);
iterator_base erase_range(iterator_base r1, iterator_base r2);
diff --git a/include/boost/unordered/detail/table.hpp b/include/boost/unordered/detail/table.hpp
index 2f4e5ebd..ab95f595 100644
--- a/include/boost/unordered/detail/table.hpp
+++ b/include/boost/unordered/detail/table.hpp
@@ -652,10 +652,20 @@ namespace boost { namespace unordered_detail {
return *it ? this->erase_group(it, bucket) : 0;
}
+ template
+ void hash_table::erase(iterator_base r)
+ {
+ BOOST_ASSERT(r.node_);
+ --this->size_;
+ node::unlink_node(*r.bucket_, r.node_);
+ this->delete_node(r.node_);
+ // r has been invalidated but its bucket is still valid
+ this->recompute_begin_bucket(r.bucket_);
+ }
template
BOOST_DEDUCED_TYPENAME T::iterator_base
- hash_table::erase(iterator_base r)
+ hash_table::erase_return_iterator(iterator_base r)
{
BOOST_ASSERT(r.node_);
iterator_base next = r;
diff --git a/include/boost/unordered/unordered_map.hpp b/include/boost/unordered/unordered_map.hpp
index ef649897..712f769c 100644
--- a/include/boost/unordered/unordered_map.hpp
+++ b/include/boost/unordered/unordered_map.hpp
@@ -355,7 +355,7 @@ namespace boost
iterator erase(const_iterator position)
{
- return iterator(table_.erase(get(position)));
+ return iterator(table_.erase_return_iterator(get(position)));
}
size_type erase(const key_type& k)
@@ -368,6 +368,11 @@ namespace boost
return iterator(table_.erase_range(get(first), get(last)));
}
+ void erase_return_void(const_iterator position)
+ {
+ table_.erase(get(position));
+ }
+
void clear()
{
table_.clear();
@@ -868,7 +873,7 @@ namespace boost
iterator erase(const_iterator position)
{
- return iterator(table_.erase(get(position)));
+ return iterator(table_.erase_return_iterator(get(position)));
}
size_type erase(const key_type& k)
@@ -881,6 +886,11 @@ namespace boost
return iterator(table_.erase_range(get(first), get(last)));
}
+ void erase_return_void(const_iterator position)
+ {
+ table_.erase(get(position));
+ }
+
void clear()
{
table_.clear();
diff --git a/include/boost/unordered/unordered_set.hpp b/include/boost/unordered/unordered_set.hpp
index 59843fd6..6982cf93 100644
--- a/include/boost/unordered/unordered_set.hpp
+++ b/include/boost/unordered/unordered_set.hpp
@@ -348,7 +348,7 @@ namespace boost
iterator erase(const_iterator position)
{
- return iterator(table_.erase(get(position)));
+ return iterator(table_.erase_return_iterator(get(position)));
}
size_type erase(const key_type& k)
@@ -361,6 +361,11 @@ namespace boost
return iterator(table_.erase_range(get(first), get(last)));
}
+ void erase_return_void(const_iterator position)
+ {
+ table_.erase(get(position));
+ }
+
void clear()
{
table_.clear();
@@ -822,7 +827,7 @@ namespace boost
iterator erase(const_iterator position)
{
- return iterator(table_.erase(get(position)));
+ return iterator(table_.erase_return_iterator(get(position)));
}
size_type erase(const key_type& k)
@@ -835,6 +840,11 @@ namespace boost
return iterator(table_.erase_range(get(first), get(last)));
}
+ void erase_return_void(const_iterator position)
+ {
+ table_.erase(get(position));
+ }
+
void clear()
{
table_.clear();
diff --git a/test/unordered/erase_tests.cpp b/test/unordered/erase_tests.cpp
index eab22f4c..1bc6e4c6 100644
--- a/test/unordered/erase_tests.cpp
+++ b/test/unordered/erase_tests.cpp
@@ -112,6 +112,55 @@ void erase_tests1(Container*, test::random_generator generator = test::default_g
BOOST_TEST(x.erase(x.begin(), x.end()) == x.begin());
}
+ std::cerr<<"erase_return_void(begin()).\n";
+ {
+ test::random_values v(1000, generator);
+ Container x(v.begin(), v.end());
+ std::size_t size = x.size();
+ while(size > 0 && !x.empty())
+ {
+ BOOST_DEDUCED_TYPENAME Container::key_type key = test::get_key(*x.begin());
+ std::size_t count = x.count(key);
+ x.erase_return_void(x.begin());
+ --size;
+ BOOST_TEST(x.count(key) == count - 1);
+ BOOST_TEST(x.size() == size);
+ }
+ BOOST_TEST(x.empty());
+ }
+
+ std::cerr<<"erase_return_void(random position).\n";
+ {
+ test::random_values v(1000, generator);
+ Container x(v.begin(), v.end());
+ std::size_t size = x.size();
+ while(size > 0 && !x.empty())
+ {
+ using namespace std;
+ int index = rand() % (int) x.size();
+ BOOST_DEDUCED_TYPENAME Container::const_iterator prev, pos, next;
+ if(index == 0) {
+ prev = pos = x.begin();
+ }
+ else {
+ prev = boost::next(x.begin(), index - 1);
+ pos = boost::next(prev);
+ }
+ next = boost::next(pos);
+ BOOST_DEDUCED_TYPENAME Container::key_type key = test::get_key(*pos);
+ std::size_t count = x.count(key);
+ x.erase_return_void(pos);
+ --size;
+ if(size > 0)
+ BOOST_TEST(index == 0 ? next == x.begin() :
+ next == boost::next(prev));
+ BOOST_TEST(x.count(key) == count - 1);
+ BOOST_TEST(x.size() == size);
+ }
+ BOOST_TEST(x.empty());
+ }
+
+
std::cerr<<"clear().\n";
{
test::random_values v(500, generator);