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<flat_map>: Workaround for CWG-2369 in deduction guides #5455

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Merged
Stephan T. Lavavej (StephanTLavavej) merged 1 commit into from
May 1, 2025
Merged

<flat_map>: Workaround for CWG-2369 in deduction guides #5455

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25 changes: 17 additions & 8 deletions stl/inc/flat_map
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Original file line number Diff line number Diff line change
Expand Up @@ -29,8 +29,9 @@ _STL_DISABLE_CLANG_WARNINGS

_STD_BEGIN
template <class _Compare, class _Key_container>
concept _Valid_compare_for_container = is_invocable_v<const _Compare&, const typename _Key_container::value_type&,
const typename _Key_container::value_type&>;
concept _Valid_compare_for_container = _Not_allocator_for_container<_Compare>
&& is_invocable_v<const _Compare&, const typename _Key_container::value_type&,
const typename _Key_container::value_type&>;

template <class _Key, class _Mapped, class _KeyCompare>
struct _Flat_map_value_compare_provider {
Expand Down Expand Up @@ -1378,8 +1379,9 @@ flat_map(sorted_unique_t, _InputIterator, _InputIterator, _Compare = _Compare())
-> flat_map<_Guide_key_t<_InputIterator>, _Guide_val_t<_InputIterator>, _Compare>;

#ifdef __cpp_lib_byte
// TRANSITION, CWG-2369, should just use constrained template parameters.
template <_RANGES input_range _Rng, _Not_allocator_for_container _Compare = less<_Range_key_type<_Rng>>,
_Allocator_for_container _Allocator = allocator<byte>>
class _Allocator = allocator<byte>, enable_if_t<_Allocator_for_container<_Allocator>, int> = 0>
flat_map(from_range_t, _Rng&&, _Compare = _Compare(), _Allocator = _Allocator())
-> flat_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Compare,
vector<_Range_key_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_key_type<_Rng>>>,
Expand All @@ -1389,13 +1391,16 @@ template <_RANGES input_range _Rng, _Not_allocator_for_container _Compare = less
flat_map(from_range_t, _Rng&&, _Compare = _Compare()) -> flat_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>,
_Compare, vector<_Range_key_type<_Rng>>, vector<_Range_mapped_type<_Rng>>>;

template <_RANGES input_range _Rng, _Not_allocator_for_container _Compare, _Allocator_for_container _Allocator>
// TRANSITION, CWG-2369, should just use constrained template parameters.
template <_RANGES input_range _Rng, _Not_allocator_for_container _Compare, class _Allocator,
enable_if_t<_Allocator_for_container<_Allocator>, int> = 0>
flat_map(from_range_t, _Rng&&, _Compare, _Allocator) -> flat_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>,
_Compare, vector<_Range_key_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_key_type<_Rng>>>,
vector<_Range_mapped_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_mapped_type<_Rng>>>>;
#endif // ^^^ !defined(__cpp_lib_byte) ^^^

template <_RANGES input_range _Rng, _Allocator_for_container _Allocator>
// TRANSITION, CWG-2369, should just use constrained template parameters.
template <_RANGES input_range _Rng, class _Allocator, enable_if_t<_Allocator_for_container<_Allocator>, int> = 0>
flat_map(from_range_t, _Rng&&, _Allocator) -> flat_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>,
less<_Range_key_type<_Rng>>, vector<_Range_key_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_key_type<_Rng>>>,
vector<_Range_mapped_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_mapped_type<_Rng>>>>;
Expand Down Expand Up @@ -1543,8 +1548,9 @@ flat_multimap(sorted_equivalent_t, _InputIterator, _InputIterator, _Compare = _C
-> flat_multimap<_Guide_key_t<_InputIterator>, _Guide_val_t<_InputIterator>, _Compare>;

#ifdef __cpp_lib_byte
// TRANSITION, CWG-2369, should just use constrained template parameters.
template <_RANGES input_range _Rng, _Not_allocator_for_container _Compare = less<_Range_key_type<_Rng>>,
_Allocator_for_container _Allocator = allocator<byte>>
class _Allocator = allocator<byte>, enable_if_t<_Allocator_for_container<_Allocator>, int> = 0>
flat_multimap(from_range_t, _Rng&&, _Compare = _Compare(), _Allocator = _Allocator())
-> flat_multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Compare,
vector<_Range_key_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_key_type<_Rng>>>,
Expand All @@ -1554,14 +1560,17 @@ template <_RANGES input_range _Rng, _Not_allocator_for_container _Compare = less
flat_multimap(from_range_t, _Rng&&, _Compare = _Compare()) -> flat_multimap<_Range_key_type<_Rng>,
_Range_mapped_type<_Rng>, _Compare, vector<_Range_key_type<_Rng>>, vector<_Range_mapped_type<_Rng>>>;

template <_RANGES input_range _Rng, _Not_allocator_for_container _Compare, _Allocator_for_container _Allocator>
// TRANSITION, CWG-2369, should just use constrained template parameters.
template <_RANGES input_range _Rng, _Not_allocator_for_container _Compare, class _Allocator,
enable_if_t<_Allocator_for_container<_Allocator>, int> = 0>
flat_multimap(from_range_t, _Rng&&, _Compare, _Allocator)
-> flat_multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Compare,
vector<_Range_key_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_key_type<_Rng>>>,
vector<_Range_mapped_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_mapped_type<_Rng>>>>;
#endif // ^^^ !defined(__cpp_lib_byte) ^^^

template <_RANGES input_range _Rng, _Allocator_for_container _Allocator>
// TRANSITION, CWG-2369, should just use constrained template parameters.
template <_RANGES input_range _Rng, class _Allocator, enable_if_t<_Allocator_for_container<_Allocator>, int> = 0>
flat_multimap(from_range_t, _Rng&&, _Allocator) -> flat_multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>,
less<_Range_key_type<_Rng>>, vector<_Range_key_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_key_type<_Rng>>>,
vector<_Range_mapped_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_mapped_type<_Rng>>>>;
Expand Down
8 changes: 4 additions & 4 deletions tests/libcxx/expected_results.txt
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Expand Up @@ -232,10 +232,6 @@ std/strings/c.strings/cuchar.compile.pass.cpp FAIL

# P0429R9 <flat_map>

# FIXME! error: no type named 'value_type' in 'std::greater<int>'
std/containers/container.adaptors/flat.map/flat.map.cons/deduct.pass.cpp FAIL
std/containers/container.adaptors/flat.multimap/flat.multimap.cons/deduct.pass.cpp FAIL

# FIXME! Assertion failed: m.keys().size() == m.values().size()
# [flat.map.defn] doesn't declare a move constructor, which seems to imply that moving from a flat_map should behave
# as if the move constructor were implicitly defined, i.e. it can't restore the invariants
Expand All @@ -259,6 +255,8 @@ std/containers/container.adaptors/flat.multimap/flat.multimap.cons/move.pass.cpp
# FIXME! warning C4242: 'initializing': conversion from '_Ty' to '_Ty2', possible loss of data
std/containers/container.adaptors/flat.map/flat.map.cons/copy_assign.pass.cpp:0 FAIL
std/containers/container.adaptors/flat.map/flat.map.cons/copy_assign.pass.cpp:1 FAIL
std/containers/container.adaptors/flat.map/flat.map.cons/deduct.pass.cpp:0 FAIL
std/containers/container.adaptors/flat.map/flat.map.cons/deduct.pass.cpp:1 FAIL
std/containers/container.adaptors/flat.map/flat.map.cons/deduct_pmr.pass.cpp:0 FAIL
std/containers/container.adaptors/flat.map/flat.map.cons/deduct_pmr.pass.cpp:1 FAIL
std/containers/container.adaptors/flat.map/flat.map.cons/initializer_list.pass.cpp:0 FAIL
Expand All @@ -283,6 +281,8 @@ std/containers/container.adaptors/flat.multimap/flat.multimap.cons/containers.pa
std/containers/container.adaptors/flat.multimap/flat.multimap.cons/containers.pass.cpp:1 FAIL
std/containers/container.adaptors/flat.multimap/flat.multimap.cons/copy_assign.pass.cpp:0 FAIL
std/containers/container.adaptors/flat.multimap/flat.multimap.cons/copy_assign.pass.cpp:1 FAIL
std/containers/container.adaptors/flat.multimap/flat.multimap.cons/deduct.pass.cpp:0 FAIL
std/containers/container.adaptors/flat.multimap/flat.multimap.cons/deduct.pass.cpp:1 FAIL
std/containers/container.adaptors/flat.multimap/flat.multimap.cons/deduct_pmr.pass.cpp:0 FAIL
std/containers/container.adaptors/flat.multimap/flat.multimap.cons/deduct_pmr.pass.cpp:1 FAIL
std/containers/container.adaptors/flat.multimap/flat.multimap.cons/initializer_list.pass.cpp:0 FAIL
Expand Down