libstdc++: [_GLIBCXX_DEBUG] Reduce performance impact on std::erase_if

Bypass the _GLIBCXX_DEBUG additional checks in std::__detail::__erase_node_if used
by all implementations of std::erase_if for node based containers.

libstdc++-v3/ChangeLog:

	* include/bits/erase_if.h (__erase_nodes_if): Add _UnsafeContainer template
	parameter. Use it to get iterators to work with.
	* include/debug/macros.h (__glibcxx_check_erase2): New.
	* include/debug/map.h (map<>::erase(_Base_const_iterator)): New.
	(map<>::erase(const_iterator)): Use latter.
	* include/debug/multimap.h (multimap<>::erase(_Base_const_iterator)): New.
	(multimap<>::erase(const_iterator)): Use latter.
	* include/debug/multiset.h (multiset<>::erase(_Base_const_iterator)): New.
	(multiset<>::erase(const_iterator)): Use latter.
	* include/debug/set.h (set<>::erase(_Base_const_iterator)): New.
	(set<>::erase(const_iterator)): Use latter.
	* include/debug/unordered_map (unordered_map<>::erase(_Base_const_iterator)): New.
	(unordered_multimap<>::erase(const_iterator)): New.
	* include/debug/unordered_set (unordered_set<>::erase(_Base_const_iterator)): New.
	(unordered_multiset<>::erase(const_iterator)): New.
	* include/experimental/map (erase_if): Adapt.
	* include/experimental/set (erase_if): Adapt.
	* include/experimental/unordered_map (erase_if): Adapt.
	* include/experimental/unordered_set (erase_if): Adapt.
	* include/std/map (erase_if): Adapt.
	* include/std/set (erase_if): Adapt.
	* include/std/unordered_map (erase_if): Adapt.
	* include/std/unordered_set (erase_if): Adapt.

4 files changed, 38 insertions, 8 deletions

diff --git a/libstdc++-v3/include/experimental/map b/libstdc++-v3/include/experimental/map
index 0c0f42222f5..13304320232 100644
--- a/libstdc++-v3/include/experimental/map
+++ b/libstdc++-v3/include/experimental/map
@@ -50,13 +50,21 @@ inline namespace fundamentals_v2
 	   typename _Predicate>
     inline void
     erase_if(map<_Key, _Tp, _Compare, _Alloc>& __cont, _Predicate __pred)
-    { std::__detail::__erase_nodes_if(__cont, __pred); }
+    {
+      const _GLIBCXX_STD_C::map<_Key, _Tp, _Compare, _Alloc>&
+	__ucont = __cont;
+      std::__detail::__erase_nodes_if(__cont, __ucont, __pred);
+    }
 
   template<typename _Key, typename _Tp, typename _Compare, typename _Alloc,
 	   typename _Predicate>
     inline void
     erase_if(multimap<_Key, _Tp, _Compare, _Alloc>& __cont, _Predicate __pred)
-    { std::__detail::__erase_nodes_if(__cont, __pred); }
+    {
+      const _GLIBCXX_STD_C::multimap<_Key, _Tp, _Compare, _Alloc>&
+	__ucont = __cont;
+      std::__detail::__erase_nodes_if(__cont, __ucont, __pred);
+    }
 
   namespace pmr {
     template<typename _Key, typename _Tp, typename _Compare = less<_Key>>
diff --git a/libstdc++-v3/include/experimental/set b/libstdc++-v3/include/experimental/set
index c3f5433e995..2a56ede5cf1 100644
--- a/libstdc++-v3/include/experimental/set
+++ b/libstdc++-v3/include/experimental/set
@@ -50,13 +50,19 @@ inline namespace fundamentals_v2
 	   typename _Predicate>
     inline void
     erase_if(set<_Key, _Compare, _Alloc>& __cont, _Predicate __pred)
-    { std::__detail::__erase_nodes_if(__cont, __pred); }
+    {
+      const _GLIBCXX_STD_C::set<_Key, _Compare, _Alloc>& __ucont = __cont;
+      std::__detail::__erase_nodes_if(__cont, __ucont, __pred);
+    }
 
   template<typename _Key, typename _Compare, typename _Alloc,
 	   typename _Predicate>
     inline void
     erase_if(multiset<_Key, _Compare, _Alloc>& __cont, _Predicate __pred)
-    { std::__detail::__erase_nodes_if(__cont, __pred); }
+    {
+      const _GLIBCXX_STD_C::multiset<_Key, _Compare, _Alloc>& __ucont = __cont;
+      std::__detail::__erase_nodes_if(__cont, __ucont, __pred);
+    }
 
   namespace pmr {
     template<typename _Key, typename _Compare = less<_Key>>
diff --git a/libstdc++-v3/include/experimental/unordered_map b/libstdc++-v3/include/experimental/unordered_map
index 0b915ab13e5..69f209d83e7 100644
--- a/libstdc++-v3/include/experimental/unordered_map
+++ b/libstdc++-v3/include/experimental/unordered_map
@@ -51,14 +51,22 @@ inline namespace fundamentals_v2
     inline void
     erase_if(unordered_map<_Key, _Tp, _Hash, _CPred, _Alloc>& __cont,
 	     _Predicate __pred)
-    { std::__detail::__erase_nodes_if(__cont, __pred); }
+    {
+      const _GLIBCXX_STD_C::unordered_map<_Key, _Tp, _Hash, _CPred, _Alloc>&
+	__ucont = __cont;
+      std::__detail::__erase_nodes_if(__cont, __ucont, __pred);
+    }
 
   template<typename _Key, typename _Tp, typename _Hash, typename _CPred,
 	   typename _Alloc, typename _Predicate>
     inline void
     erase_if(unordered_multimap<_Key, _Tp, _Hash, _CPred, _Alloc>& __cont,
 	     _Predicate __pred)
-    { std::__detail::__erase_nodes_if(__cont, __pred); }
+    {
+      const _GLIBCXX_STD_C::unordered_multimap<_Key, _Tp, _Hash, _CPred, _Alloc>&
+	__ucont = __cont;
+      std::__detail::__erase_nodes_if(__cont, __ucont, __pred);
+    }
 
   namespace pmr {
     template<typename _Key, typename _Tp, typename _Hash = hash<_Key>,
diff --git a/libstdc++-v3/include/experimental/unordered_set b/libstdc++-v3/include/experimental/unordered_set
index 87db4464401..fbab7e7ddb5 100644
--- a/libstdc++-v3/include/experimental/unordered_set
+++ b/libstdc++-v3/include/experimental/unordered_set
@@ -51,14 +51,22 @@ inline namespace fundamentals_v2
     inline void
     erase_if(unordered_set<_Key, _Hash, _CPred, _Alloc>& __cont,
 	     _Predicate __pred)
-    { std::__detail::__erase_nodes_if(__cont, __pred); }
+    {
+      const _GLIBCXX_STD_C::unordered_set<_Key, _Hash, _CPred, _Alloc>&
+	__ucont = __cont;
+      std::__detail::__erase_nodes_if(__cont, __ucont, __pred);
+    }
 
   template<typename _Key, typename _Hash, typename _CPred, typename _Alloc,
 	   typename _Predicate>
     inline void
     erase_if(unordered_multiset<_Key, _Hash, _CPred, _Alloc>& __cont,
 	     _Predicate __pred)
-    { std::__detail::__erase_nodes_if(__cont, __pred); }
+    {
+      const _GLIBCXX_STD_C::unordered_multiset<_Key, _Hash, _CPred, _Alloc>&
+	__ucont = __cont;
+      std::__detail::__erase_nodes_if(__cont, __ucont, __pred);
+    }
 
   namespace pmr {
     template<typename _Key, typename _Hash = hash<_Key>,