libstdc++: Fix conversions to key/value types for hash table insertion [PR115285]

The conversions to key_type and value_type that are performed when
inserting into _Hashtable need to be fixed to do any required
conversions explicitly. The current code assumes that conversions from
the parameter to the key_type or value_type can be done implicitly,
which isn't necessarily true.

Remove the _S_forward_key function which doesn't handle all cases and
either forward the parameter if it already has type cv key_type, or
explicitly construct a temporary of type key_type.

Similarly, the _ConvertToValueType specialization for maps doesn't
handle all cases either, for std::pair arguments only some value
categories are handled. Remove _ConvertToValueType and for the _M_insert
function for unique keys, either forward the argument unchanged or
explicitly construct a temporary of type value_type.

For the _M_insert overload for non-unique keys we don't need any
conversion at all, we can just forward the argument directly to where we
construct a node.

libstdc++-v3/ChangeLog:

	PR libstdc++/115285
	* include/bits/hashtable.h (_Hashtable::_S_forward_key): Remove.
	(_Hashtable::_M_insert_unique_aux): Replace _S_forward_key with
	a static_cast to a type defined using conditional_t.
	(_Hashtable::_M_insert): Replace _ConvertToValueType with a
	static_cast to a type defined using conditional_t.
	* include/bits/hashtable_policy.h (_ConvertToValueType): Remove.
	* testsuite/23_containers/unordered_map/insert/115285.cc: New test.
	* testsuite/23_containers/unordered_set/insert/115285.cc: New test.
	* testsuite/23_containers/unordered_set/96088.cc: Adjust
	expected number of allocations.

0 files changed, 0 insertions, 0 deletions