libstdc++: Add fancy pointer support to std::forward_list [PR57272]

This takes a very similar approach to the changes for std::list.

libstdc++-v3/ChangeLog:

	PR libstdc++/57272
	* include/bits/forward_list.h (_GLIBCXX_USE_ALLOC_PTR_FOR_LIST):
	Define.
	(_Fwd_list_node_base::_M_base_ptr): New member functions.
	(_Fwd_list_node::_M_node_ptr): New member function.
	(_Fwd_list_iterator, _Fwd_list_const_iterator): Make internal
	member functions and data member private. Declare forward_list
	and _Fwd_list_base as friends.
	(__fwdlist::_Node_base, __fwdlist::_Node, __fwdlist::_Iterator):
	New class templates.
	(__fwdlist::_Node_traits): New class template.
	(_Fwd_list_base): Use _Node_traits to get types. Use _Base_ptr
	instad of _Fwd_list_node_base*. Use _M_base_ptr() instead of
	taking address of head node.
	(forward_list): Likewise.
	(_Fwd_list_base::_M_get_node): Do not define for versioned
	namespace.
	(_Fwd_list_base::_M_put_node): Only convert pointer if needed.
	(_Fwd_list_base::_M_create_node): Use __allocate_guarded_obj.
	(_Fwd_list_base::_M_destroy_node): New member function.
	* include/bits/forward_list.tcc (_Fwd_list_base::_M_insert_after)
	(forward_list::_M_splice_after, forward_list::insert_after): Use
	const_iterator::_M_const_cast() instead of casting pointers.
	(_Fwd_list_base::_M_erase_after): Use _M_destroy_node.
	(forward_list::remove, forward_list::remove_if): Only do
	downcasts when accessing the value.
	(forward_list::sort): Likewise.
	* testsuite/23_containers/forward_list/capacity/1.cc: Check
	max_size for new node type.
	* testsuite/23_containers/forward_list/capacity/node_sizes.cc:
	New test.
	* testsuite/23_containers/forward_list/requirements/explicit_instantiation/alloc_ptr.cc:
	New test.
	* testsuite/23_containers/forward_list/requirements/explicit_instantiation/alloc_ptr_ignored.cc:
	New test.

0 files changed, 0 insertions, 0 deletions