libstdc++: debug impls for heterogeneous erasure overloads (P2077) [PR117404]

Implement the debug versions of new overloads from P2077.

libstdc++-v3/ChangeLog:
	PR libstdc++/117404
	* include/debug/map.h (extract, erase): Define overloads.
	* include/debug/multimap.h: Same.
	* include/debug/multiset.h: Same.
	* include/debug/set.h: Same.
	* include/debug/unordered_map: Same (2x).
	* include/debug/unordered_set: Same (2x), rename some locals.

libstdc++-v3/include/debug/map.h

@@ -476,6 +476,18 @@ namespace __debug
 	return {};
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_tree_key<map> _Kt>
+	node_type
+	extract(_Kt&& __key)
+	{
+	  const auto __position = find(__key);
+	  if (__position != end())
+	    return extract(__position);
+	  return {};
+	}
+# endif
+
       insert_return_type
       insert(node_type&& __nh)
       {
@@ -538,6 +550,26 @@ namespace __debug
 	  }
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      // Note that for some types _Kt this may erase more than
+      // one element, such as if _Kt::operator< checks only part
+      // of the key.
+      template <__heterogeneous_tree_key<map> _Kt>
+	size_type
+	erase(_Kt&& __x)
+	{
+	  auto __victims = _Base::equal_range(__x);
+	  size_type __count = 0;
+	  for (auto __victim = __victims.first; __victim != __victims.second;)
+	    {
+	      this->_M_invalidate_if(_Equal(__victim));
+	      _Base::erase(__victim++);
+	      ++__count;
+	    }
+	  return __count;
+	}
+# endif
+
 #if __cplusplus >= 201103L
       iterator
       erase(const_iterator __first, const_iterator __last)

libstdc++-v3/include/debug/multimap.h

@@ -360,6 +360,18 @@ namespace __debug
 	return {};
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_tree_key<multimap> _Kt>
+	node_type
+	extract(_Kt&& __key)
+	{
+	  const auto __position = find(__key);
+	  if (__position != end())
+	    return extract(__position);
+	  return {};
+	}
+# endif
+
       iterator
       insert(node_type&& __nh)
       { return { _Base::insert(std::move(__nh)), this }; }
@@ -420,6 +432,23 @@ namespace __debug
 	return __count;
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_tree_key<multimap> _Kt>
+	size_type
+	erase(_Kt&& __x)
+	{
+	  auto __victims = _Base::equal_range(__x);
+	  size_type __count = 0;
+	  for (auto __victim = __victims.first; __victim != __victims.second;)
+	    {
+	      this->_M_invalidate_if(_Equal(__victim));
+	      _Base::erase(__victim++);
+	      ++__count;
+	    }
+	  return __count;
+	}
+# endif
+
 #if __cplusplus >= 201103L
       iterator
       erase(const_iterator __first, const_iterator __last)

libstdc++-v3/include/debug/multiset.h

@@ -331,6 +331,18 @@ namespace __debug
 	return {};
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_tree_key<multiset> _Kt>
+	node_type
+	extract(_Kt&& __key)
+	{
+	  const auto __position = find(__key);
+	  if (__position != end())
+	    return extract(__position);
+	  return {};
+	}
+#endif
+
       iterator
       insert(node_type&& __nh)
       { return { _Base::insert(std::move(__nh)), this }; }
@@ -387,6 +399,23 @@ namespace __debug
 	return __count;
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_tree_key<multiset> _Kt>
+	size_type
+	erase(_Kt&& __x)
+	{
+	  auto __victims = _Base::equal_range(__x);
+	  size_type __count = 0;
+	  for (auto __victim = __victims.first; __victim != __victims.second;)
+	    {
+	      this->_M_invalidate_if(_Equal(__victim));
+	      _Base::erase(__victim++);
+	      ++__count;
+	    }
+	  return __count;
+	}
+# endif
+
 #if __cplusplus >= 201103L
       _GLIBCXX_ABI_TAG_CXX11
       iterator

libstdc++-v3/include/debug/set.h

@@ -340,6 +340,18 @@ namespace __debug
 	return {};
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_tree_key<set> _Kt>
+	node_type
+	extract(_Kt&& __key)
+	{
+	  const auto __position = find(__key);
+	  if (__position != end())
+	    return extract(__position);
+	  return {};
+	}
+#endif
+
       insert_return_type
       insert(node_type&& __nh)
       {
@@ -398,6 +410,26 @@ namespace __debug
 	  }
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      // Note that for some types _Kt this may erase more than
+      // one element, such as if _Kt::operator< checks only part
+      // of the key.
+      template <__heterogeneous_tree_key<set> _Kt>
+	size_type
+	erase(_Kt&& __x)
+	{
+	  auto __victims = _Base::equal_range(__x);
+	  size_type __count = 0;
+	  for (auto __victim = __victims.first; __victim != __victims.second;)
+	    {
+	      this->_M_invalidate_if(_Equal(__victim));
+	      _Base::erase(__victim++);
+	      ++__count;
+	    }
+	  return __count;
+	}
+#endif
+
 #if __cplusplus >= 201103L
       _GLIBCXX_ABI_TAG_CXX11
       iterator

libstdc++-v3/include/debug/unordered_map

@@ -581,6 +581,18 @@ namespace __debug
 	return {};
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_hash_key<unordered_map> _Kt>
+	node_type
+	extract(_Kt&& __key)
+	{
+	  const auto __position = _Base::find(__key);
+	  if (__position != _Base::end())
+	    return _M_extract(__position);
+	  return {};
+	}
+#endif
+
       insert_return_type
       insert(node_type&& __nh)
       {
@@ -713,6 +725,18 @@ namespace __debug
 	return __ret;
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_hash_key<unordered_map> _Kt>
+	size_type
+	erase(_Kt&& __key)
+	{
+	  auto __victim = _Base::find(__key);
+	  if (__victim != _Base::end())
+	    return _M_erase(__victim), 1;
+	  return 0;
+	}
+#endif
+
       iterator
       erase(const_iterator __it)
       {
@@ -1381,6 +1405,18 @@ namespace __debug
 	return {};
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_hash_key<unordered_multimap> _Kt>
+	node_type
+	extract(_Kt&& __key)
+	{
+	  const auto __position = _Base::find(__key);
+	  if (__position != _Base::end())
+	    return _M_extract(__position);
+	  return {};
+	}
+#endif
+
       iterator
       insert(node_type&& __nh)
       { return { _Base::insert(std::move(__nh)), this }; }
@@ -1510,6 +1546,23 @@ namespace __debug
 	return __ret;
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_hash_key<unordered_multimap> _Kt>
+	size_type
+	erase(_Kt&& __key)
+	{
+	  size_type __count(0);
+	  auto __victims = _Base::equal_range(__key);
+	  for (auto __victim = __victims.first; __victim != __victims.second;)
+	    {
+	      _M_invalidate(__victim);
+	      __victim = _Base::erase(__victim);
+	      ++__count;
+	    }
+	  return __count;
+	}
+#endif
+
       iterator
       erase(const_iterator __it)
       {

libstdc++-v3/include/debug/unordered_set

@@ -468,6 +468,18 @@ namespace __debug
 	return {};
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_hash_key<unordered_set> _Kt>
+	node_type
+	extract(_Kt&& __key)
+	{
+	  const auto __position = _Base::find(__key);
+	  if (__position != _Base::end())
+	    return _M_extract(__position);
+	  return {};
+	}
+#endif
+
       insert_return_type
       insert(node_type&& __nh)
       {
@@ -598,6 +610,18 @@ namespace __debug
 	return __ret;
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_hash_key<unordered_set> _Kt>
+	size_type
+	erase(_Kt&& __key)
+	{
+	  auto __victim = _Base::find(__key);
+	  if (__victim != _Base::end())
+	    return _M_erase(__victim), 1;
+	  return 0;
+	}
+#endif
+
       iterator
       erase(const_iterator __it)
       {
@@ -1202,6 +1226,17 @@ namespace __debug
 	return {};
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_hash_key<unordered_multiset> _Kt>
+	node_type
+	extract(const _Kt& __key)
+	{
+	  const auto __position = _Base::find(__key);
+	  return __position != _Base::end() ?
+	    _M_extract(__position) : node_type{};
+	}
+#endif
+
       iterator
       insert(node_type&& __nh)
       { return { _Base::insert(std::move(__nh)), this }; }
@@ -1318,18 +1353,34 @@ namespace __debug
       size_type
       erase(const key_type& __key)
       {
-	size_type __ret(0);
-	auto __pair = _Base::equal_range(__key);
-	for (auto __victim = __pair.first; __victim != __pair.second;)
+	size_type __count(0);
+	auto __victims = _Base::equal_range(__key);
+	for (auto __victim = __victims.first; __victim != __victims.second;)
 	  {
 	    _M_invalidate(__victim);
 	    __victim = _Base::erase(__victim);
-	    ++__ret;
+	    ++__count;
 	  }
-
-	return __ret;
+	return __count;
       }
 
+# ifdef __glibcxx_associative_heterogeneous_erasure
+      template <__heterogeneous_hash_key<unordered_multiset> _Kt>
+	size_type
+	erase(_Kt&& __key)
+	{
+	  size_type __count(0);
+	  auto __victims = _Base::equal_range(__key);
+	  for (auto __victim = __victims.first; __victim != __victims.second;)
+	    {
+	      _M_invalidate(__victim);
+	      __victim = _Base::erase(__victim);
+	      ++__count;
+	    }
+	  return __count;
+	}
+#endif
+
       iterator
       erase(const_iterator __it)
       {