I think I never got a clear answer that we'll wait for stage 1 to
consider this patch so here is a ping.
On 01/12/20 8:19 am, François Dumont wrote:
Let me know if I need to reference a specific paper or any other
Standard reference here. Maybe P1690R1 I used here ?
I tried to allow the same partition trick you can have on ordered
containers (see Partition in tests) even if here elements are not
ordered so I aren't sure there can be any usage of it.
libstdc++: Add unordered containers heterogeneous lookup
Add unordered containers heterogeneous lookup member functions
find, count, contains and
equal_range in C++20. Those members are considered for overload
resolution only if hash and
equal functors used to instantiate the container have a nested
is_transparent type.
libstdc++-v3/ChangeLog:
* include/bits/stl_tree.h
(__has_is_transparent, __has_is_transparent_t): Move...
* include/bits/stl_function.h: ...here.
* include/bits/hashtable_policy.h
(_Hash_code_base<>::_M_hash_code):
Use template key type.
(_Hashtable_base<>::_M_equals): Likewise.
* include/bits/hashtable.h (_Hashtable<>::_M_find_tr,
_Hashtable<>::_M_count_tr,
_Hashtable<>::_M_equal_range_tr): New member function
templates to perform
heterogeneous lookup.
(_Hashtable<>::_M_find_before_node): Use template key type.
(_Hashtable<>::_M_find_node): Likewise.
* include/bits/unordered_map.h (unordered_map::find<>,
unordered_map::count<>,
unordered_map::contains<>, unordered_map::equal_range<>):
New member function
templates to perform heterogeneous lookup.
(unordered_multimap::find<>, unordered_multimap::count<>,
unordered_multimap::contains<>,
unordered_multimap::equal_range<>): Likewise.
* include/bits/unordered_set.h (unordered_set::find<>,
unordered_set::count<>,
unordered_set::contains<>, unordered_set::equal_range<>):
Likewise.
(unordered_multiset::find<>, unordered_multiset::count<>,
unordered_multiset::contains<>,
unordered_multiset::equal_range<>): Likewise.
* include/debug/unordered_map
(unordered_map::find<>, unordered_map::equal_range<>):
Likewise.
(unordered_multimap::find<>,
unordered_multimap::equal_range<>): Likewise.
* include/debug/unordered_set
(unordered_set::find<>, unordered_set::equal_range<>):
Likewise.
(unordered_multiset::find<>,
unordered_multiset::equal_range<>): Likewise.
* testsuite/23_containers/unordered_map/operations/1.cc:
New test.
*
testsuite/23_containers/unordered_multimap/operations/1.cc: New test.
*
testsuite/23_containers/unordered_multiset/operations/1.cc: New test.
* testsuite/23_containers/unordered_set/operations/1.cc:
New test.
Tested under Linux x86_64 normal and debug modes.
François
