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Merged
Stephan T. Lavavej (StephanTLavavej) merged 8 commits into from
Mar 13, 2024
Merged

<flat_map>: Various cleanups and bug fixes #4468

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e758cb2
Style cleanup
frederick-vs-ja Mar 10, 2024
cd7688b
Use direct-non-list-initialization
frederick-vs-ja Mar 10, 2024
9fff373
Avoid calling `distance` on non-forward input iterators
frederick-vs-ja Mar 10, 2024
e04d30d
Short-circuit evaluation of `_Hint_is_accurate`
frederick-vs-ja Mar 10, 2024
896d66f
Eliminate `_Key_equal` after `lower_bound`
frederick-vs-ja Mar 10, 2024
6d4085a
Unwrap iterators before calling algorithms
frederick-vs-ja Mar 10, 2024
406cefd
Improve tests
frederick-vs-ja Mar 10, 2024
1ab4922
Consistency change on `__cpp_lib_byte`
frederick-vs-ja Mar 10, 2024
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200 changes: 123 additions & 77 deletions stl/inc/flat_map
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Original file line number Diff line number Diff line change
Expand Up @@ -126,7 +126,7 @@ struct _Pairing_iterator_provider {
}

pointer operator->() const {
return pointer{*(*this)};
return pointer{**this};
}

_Iterator& operator++() {
Expand Down Expand Up @@ -722,8 +722,9 @@ public:
}

_NODISCARD_FRIEND auto operator<=>(const _Derived& _Left, const _Derived& _Right) {
return _STD lexicographical_compare_three_way(
_Left.cbegin(), _Left.cend(), _Right.cbegin(), _Right.cend(), _Synth_three_way{});
return _STD lexicographical_compare_three_way(_STD _Get_unwrapped(_Left.cbegin()),
_STD _Get_unwrapped(_Left.cend()), _STD _Get_unwrapped(_Right.cbegin()), _STD _Get_unwrapped(_Right.cend()),
_Synth_three_way{});
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}

friend void swap(_Derived& _Left, _Derived& _Right) noexcept {
Expand All @@ -737,7 +738,6 @@ protected:

template <class _Predicate>
size_type _Erase_if(_Predicate _Pred) {

auto _View = _View_to_mutate();
auto _Mut_first = _View.begin();
auto _Mut_last = _View.end();
Expand All @@ -764,53 +764,55 @@ protected:
const const_iterator _Begin = cbegin();
const const_iterator _End = cend();

bool _Insert_before_position = false;
bool _Insert_after_position_minus_1 = false;
if constexpr (_IsUnique) {
_Insert_before_position = (_Position == _End) || _Key_compare(_Key_val, *(_Position._Key_it));
_Insert_after_position_minus_1 = (_Position == _Begin) || _Key_compare(*(_Position._Key_it - 1), _Key_val);
} else {
_Insert_before_position = (_Position == _End) || !_Key_compare(*(_Position._Key_it), _Key_val);
_Insert_after_position_minus_1 = (_Position == _Begin) || !_Key_compare(_Key_val, *(_Position._Key_it - 1));
}
bool _Hint_is_accurate = _Insert_before_position && _Insert_after_position_minus_1;
const bool _Hint_is_accurate = [&] {
if constexpr (_IsUnique) {
if (_Position == _End || _Key_compare(_Key_val, *_Position._Key_it)) {
return _Position == _Begin || _Key_compare(_Position._Key_it[-1], _Key_val);
}
} else {
if (_Position == _End || !_Key_compare(*_Position._Key_it, _Key_val)) {
return _Position == _Begin || !_Key_compare(_Key_val, _Position._Key_it[-1]);
}
}
return false;
}();

if (_Hint_is_accurate) {
auto _Dist = _STD distance(_Begin._Key_it, _Position._Key_it);
const auto _Dist = _Position._Key_it - _Begin._Key_it;
{
key_type _Key_to_insert(_STD forward<_OtherKey>(_Key_val));
mapped_type _Mapped_to_insert(_STD forward<_MappedArgTypes>(_Args)...);
_Insert_exact(_Position, _STD move(_Key_to_insert), _STD move(_Mapped_to_insert));
}
return begin() + _Dist;
} else {
if constexpr (_OverwriteIfExists) {
if (_Key_equal(_Key_val, *(_Position._Key_it))) {
auto _Dist = _STD distance(_Begin._Key_it, _Position._Key_it);
auto _It = begin() + _Dist;
*(_It._Mapped_it) = mapped_type{_STD forward<_MappedArgTypes>(_Args)...};
return _It;
}
}

_Position = lower_bound(_Key_val);
if (_Position != _End && _Key_equal(_Key_val, *(_Position._Key_it))) {
auto _Dist = _STD distance(_Begin._Key_it, _Position._Key_it);
auto _It = begin() + _Dist;
*(_It._Mapped_it) = mapped_type{_STD forward<_MappedArgTypes>(_Args)...};
return _It;
}
} else {
_Position = lower_bound(_Key_val);
if constexpr (_OverwriteIfExists) {
if (_Key_equal(_Key_val, *_Position._Key_it)) {
const auto _Dist = _Position._Key_it - _Begin._Key_it;
const auto _It = begin() + _Dist;
*_It._Mapped_it = mapped_type(_STD forward<_MappedArgTypes>(_Args)...);
return _It;
}

const auto _Dist = _STD distance(_Begin._Key_it, _Position._Key_it);
{
key_type _Key_to_insert(_STD forward<_OtherKey>(_Key_val));
mapped_type _Mapped_to_insert(_STD forward<_MappedArgTypes>(_Args)...);
_Insert_exact(_Position, _STD move(_Key_to_insert), _STD move(_Mapped_to_insert));
_Position = lower_bound(_Key_val);
if (_Position != _End && !_Key_compare(_Key_val, *_Position._Key_it)) {
const auto _Dist = _Position._Key_it - _Begin._Key_it;
auto _It = begin() + _Dist;
*_It._Mapped_it = mapped_type(_STD forward<_MappedArgTypes>(_Args)...);
return _It;
}
return begin() + _Dist;
} else {
_Position = lower_bound(_Key_val);
}

const auto _Dist = _Position._Key_it - _Begin._Key_it;
{
key_type _Key_to_insert(_STD forward<_OtherKey>(_Key_val));
mapped_type _Mapped_to_insert(_STD forward<_MappedArgTypes>(_Args)...);
_Insert_exact(_Position, _STD move(_Key_to_insert), _STD move(_Mapped_to_insert));
}
return begin() + _Dist;
}

void _Insert_exact(const_iterator _Position, key_type&& _Key_val, mapped_type&& _Mapped_val) {
Expand Down Expand Up @@ -846,11 +848,11 @@ private:

void _Dedup() {
_Clear_flat_map_scope_guard _Guard{this};
auto _Sorted_view = _View_to_mutate();
auto _Subrange = _RANGES unique(_Sorted_view, [this](const_reference _Left, const_reference _Right) {
auto _Sorted_view = _View_to_mutate();
auto _Subrange = _RANGES unique(_Sorted_view, [this](const_reference _Left, const_reference _Right) {
return this->_Key_equal(_Left.first, _Right.first);
});
auto _Remaining_count = _STD distance(_Sorted_view.begin(), _Subrange.begin());
const auto _Remaining_count = _Subrange.begin() - _Sorted_view.begin();
_Data.keys.erase(_Data.keys.begin() + _Remaining_count, _Data.keys.end());
_Data.values.erase(_Data.values.begin() + _Remaining_count, _Data.values.end());
_Guard._Clearable = nullptr;
Expand All @@ -862,27 +864,30 @@ private:
_Clear_flat_map_scope_guard _Guard{this};

// Insert the new elements at the end
size_type _OldSize = size();
size_type _NewSize = _STD distance(_First, _Last);
const size_type _Old_size = size();
if constexpr (_Is_cpp17_fwd_iter_v<_InputIterator>) {
const auto _New_size = static_cast<size_type>(_STD distance(_First, _Last));
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_Data.keys.reserve(_Data.keys.size() + _NewSize);
_Data.values.reserve(_Data.values.size() + _NewSize);
_Data.keys.reserve(_Data.keys.size() + _New_size);
_Data.values.reserve(_Data.values.size() + _New_size);
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}

for (; _First != _Last; ++_First) {
_Data.keys.emplace_back(_STD move(_First->first));
_Data.values.emplace_back(_STD move(_First->second));
value_type _Val = *_First;
_Data.keys.emplace_back(_STD move(_Val.first));
_Data.values.emplace_back(_STD move(_Val.second));
}

// Sort the newly inserted elements
auto _Sorted_view = _View_to_mutate();
if constexpr (_NeedSorting) {
auto _Sorted_new_elements = _Sorted_view;
_Sorted_new_elements.advance(_OldSize);
_Sorted_new_elements.advance(_Old_size);
_RANGES sort(_Sorted_new_elements, value_compare(_Key_compare));
}

// Merge the newly inserted elements with the existing elements
_RANGES inplace_merge(_Sorted_view, _Sorted_view.begin() + _OldSize, value_compare(_Key_compare));
_RANGES inplace_merge(_Sorted_view, _Sorted_view.begin() + _Old_size, value_compare(_Key_compare));

if constexpr (_NeedDeduping) {
_Dedup();
Expand All @@ -903,7 +908,7 @@ private:
_NODISCARD iterator _Find(const _KeyTy& _Key_val) {
_STL_INTERNAL_STATIC_ASSERT(is_same_v<_KeyTy, key_type> || _Is_transparent_v<key_compare>);
iterator _Position = lower_bound(_Key_val);
if (_Position != end() && _Key_equal(_Position->first, _Key_val)) {
if (_Position != end() && !_Key_compare(_Key_val, _Position->first)) {
return _Position;
} else {
return end();
Expand All @@ -914,7 +919,7 @@ private:
_NODISCARD const_iterator _Find(const _KeyTy& _Key_val) const {
_STL_INTERNAL_STATIC_ASSERT(is_same_v<_KeyTy, key_type> || _Is_transparent_v<key_compare>);
const_iterator _Position = lower_bound(_Key_val);
if (_Position != cend() && _Key_equal(_Position->first, _Key_val)) {
if (_Position != cend() && !_Key_compare(_Key_val, _Position->first)) {
return _Position;
} else {
return cend();
Expand All @@ -936,35 +941,55 @@ private:
template <class _KeyTy>
_NODISCARD iterator _Lower_bound(const _KeyTy& _Key_val) {
_STL_INTERNAL_STATIC_ASSERT(is_same_v<_KeyTy, key_type> || _Is_transparent_v<key_compare>);
auto _Key_it = _STD lower_bound(_Data.keys.cbegin(), _Data.keys.cend(), _Key_val, _Key_compare);
auto _Dist = _STD distance(_Data.keys.cbegin(), _Key_it);
const auto _Key_unchecked_begin = _STD _Get_unwrapped(_Data.keys.cbegin());
const auto _Key_unchecked_it =
_STD lower_bound(_Key_unchecked_begin, _STD _Get_unwrapped(_Data.keys.cend()), _Key_val, _Key_compare);
const auto _Dist = _Key_unchecked_it - _Key_unchecked_begin;

auto _Key_it = _Data.keys.cbegin();
_STD _Seek_wrapped(_Key_it, _Key_unchecked_it);
auto _Val_it = _Data.values.begin() + _Dist;
return iterator{_STD move(_Key_it), _STD move(_Val_it)};
}

template <class _KeyTy>
_NODISCARD const_iterator _Lower_bound(const _KeyTy& _Key_val) const {
_STL_INTERNAL_STATIC_ASSERT(is_same_v<_KeyTy, key_type> || _Is_transparent_v<key_compare>);
auto _Key_it = _STD lower_bound(_Data.keys.cbegin(), _Data.keys.cend(), _Key_val, _Key_compare);
auto _Dist = _STD distance(_Data.keys.cbegin(), _Key_it);
const auto _Key_unchecked_begin = _STD _Get_unwrapped(_Data.keys.cbegin());
const auto _Key_unchecked_it =
_STD lower_bound(_Key_unchecked_begin, _STD _Get_unwrapped(_Data.keys.cend()), _Key_val, _Key_compare);
const auto _Dist = _Key_unchecked_it - _Key_unchecked_begin;

auto _Key_it = _Data.keys.cbegin();
_STD _Seek_wrapped(_Key_it, _Key_unchecked_it);
auto _Val_it = _Data.values.cbegin() + _Dist;
return const_iterator{_STD move(_Key_it), _STD move(_Val_it)};
}

template <class _KeyTy>
_NODISCARD iterator _Upper_bound(const _KeyTy& _Key_val) {
_STL_INTERNAL_STATIC_ASSERT(is_same_v<_KeyTy, key_type> || _Is_transparent_v<key_compare>);
auto _Key_it = _STD upper_bound(_Data.keys.cbegin(), _Data.keys.cend(), _Key_val, _Key_compare);
auto _Dist = _STD distance(_Data.keys.cbegin(), _Key_it);
const auto _Key_unchecked_begin = _STD _Get_unwrapped(_Data.keys.cbegin());
const auto _Key_unchecked_it =
_STD upper_bound(_Key_unchecked_begin, _STD _Get_unwrapped(_Data.keys.cend()), _Key_val, _Key_compare);
const auto _Dist = _Key_unchecked_it - _Key_unchecked_begin;

auto _Key_it = _Data.keys.cbegin();
_STD _Seek_wrapped(_Key_it, _Key_unchecked_it);
auto _Val_it = _Data.values.begin() + _Dist;
return iterator{_STD move(_Key_it), _STD move(_Val_it)};
}

template <class _KeyTy>
_NODISCARD const_iterator _Upper_bound(const _KeyTy& _Key_val) const {
_STL_INTERNAL_STATIC_ASSERT(is_same_v<_KeyTy, key_type> || _Is_transparent_v<key_compare>);
auto _Key_it = _STD upper_bound(_Data.keys.cbegin(), _Data.keys.cend(), _Key_val, _Key_compare);
auto _Dist = _STD distance(_Data.keys.cbegin(), _Key_it);
const auto _Key_unchecked_begin = _STD _Get_unwrapped(_Data.keys.cbegin());
const auto _Key_unchecked_it =
_STD upper_bound(_Key_unchecked_begin, _STD _Get_unwrapped(_Data.keys.cend()), _Key_val, _Key_compare);
const auto _Dist = _Key_unchecked_it - _Key_unchecked_begin;

auto _Key_it = _Data.keys.cbegin();
_STD _Seek_wrapped(_Key_it, _Key_unchecked_it);
auto _Val_it = _Data.values.cbegin() + _Dist;
return const_iterator{_STD move(_Key_it), _STD move(_Val_it)};
}
Expand Down Expand Up @@ -1167,9 +1192,9 @@ private:
const auto _Position = this->find(_Key_val);
if (_Position == this->end()) {
_Xout_of_range("std::flat_map::at: the specified key does not exist.");
} else {
return _Position->second;
}

return _Position->second;
}

template <class _KeyTy>
Expand All @@ -1178,27 +1203,27 @@ private:
const auto _Position = this->find(_Key_val);
if (_Position == this->end()) {
_Xout_of_range("std::flat_map::at: the specified key does not exist.");
} else {
return _Position->second;
}

return _Position->second;
}

template <class _KeyTy, class... _MappedArgTypes>
pair<iterator, bool> _Try_emplace(_KeyTy&& _Key_val, _MappedArgTypes&&... _Mapped_args) {
auto _Key_it = _STD lower_bound(_Data.keys.begin(), _Data.keys.end(), _Key_val, _Key_compare);
if (_Key_it != _Data.keys.end() && _Key_equal(*_Key_it, _STD forward<_KeyTy>(_Key_val))) {
if (_Key_it != _Data.keys.end() && !_Key_compare(_STD forward<_KeyTy>(_Key_val), *_Key_it)) {
// Already exists
return {this->begin() + _STD distance(_Data.keys.begin(), _Key_it), false};
} else {
// Need to insert
auto _Index = _STD distance(_Data.keys.begin(), _Key_it);
{
key_type _Key_to_insert(_STD forward<_KeyTy>(_Key_val));
mapped_type _Mapped_to_insert(_STD forward<_MappedArgTypes>(_Mapped_args)...);
this->_Insert_exact(this->cbegin() + _Index, _STD move(_Key_to_insert), _STD move(_Mapped_to_insert));
}
return {this->begin() + _Index, true};
return {this->begin() + (_Key_it - _Data.keys.begin()), false};
}

// Need to insert
const auto _Index = _Key_it - _Data.keys.begin();
{
key_type _Key_to_insert(_STD forward<_KeyTy>(_Key_val));
mapped_type _Mapped_to_insert(_STD forward<_MappedArgTypes>(_Mapped_args)...);
this->_Insert_exact(this->cbegin() + _Index, _STD move(_Key_to_insert), _STD move(_Mapped_to_insert));
}
return {this->begin() + _Index, true};
}

template <class _KeyTy, class _MappedTy>
Expand Down Expand Up @@ -1257,7 +1282,17 @@ 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>>>,
vector<_Range_mapped_type<_Rng>, _Rebind_alloc_t<_Allocator, _Range_mapped_type<_Rng>>>>;
#endif // defined(__cpp_lib_byte)
#else // ^^^ defined(__cpp_lib_byte) / !defined(__cpp_lib_byte) vvv
template <_RANGES input_range _Rng, class _Compare = less<_Range_key_type<_Rng>>>
flat_map(from_range_t, _Rng&&, _Compare = _Compare()) -> flat_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>,
_Compare, vector<_Range_key_type<_Rng>, allocator<_Range_key_type<_Rng>>>,
vector<_Range_mapped_type<_Rng>, allocator<_Range_mapped_type<_Rng>>>>;
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template <_RANGES input_range _Rng, class _Compare, class _Allocator>
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, class _Allocator>
flat_map(from_range_t, _Rng&&, _Allocator) -> flat_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>,
Expand Down Expand Up @@ -1333,7 +1368,7 @@ private:
template <class _KeyTy, class _MappedTy>
iterator _Emplace_key_mapped(_KeyTy&& _Key_val, _MappedTy&& _Mapped_val) {
const auto _Key_it = _STD lower_bound(_Data.keys.begin(), _Data.keys.end(), _Key_val, _Key_compare);
const auto _Index = _STD distance(_Data.keys.begin(), _Key_it);
const auto _Index = _Key_it - _Data.keys.begin();

{
_Key _Key_to_insert(_STD forward<_KeyTy>(_Key_val));
Expand Down Expand Up @@ -1385,7 +1420,18 @@ flat_multimap(from_range_t, _Rng&&, _Compare = _Compare(), _Allocator = _Allocat
-> 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)
#else // ^^^ defined(__cpp_lib_byte) / !defined(__cpp_lib_byte) vvv
template <_RANGES input_range _Rng, class _Compare = less<_Range_key_type<_Rng>>>
flat_multimap(from_range_t, _Rng&&, _Compare = _Compare()) -> flat_multimap<_Range_key_type<_Rng>,
_Range_mapped_type<_Rng>, _Compare, vector<_Range_key_type<_Rng>, allocator<_Range_key_type<_Rng>>>,
vector<_Range_mapped_type<_Rng>, allocator<_Range_mapped_type<_Rng>>>>;

template <_RANGES input_range _Rng, class _Compare, class _Allocator>
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, class _Allocator>
flat_multimap(from_range_t, _Rng&&, _Allocator) -> flat_multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>,
Expand Down
12 changes: 6 additions & 6 deletions tests/std/include/test_header_units_and_modules.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -251,17 +251,17 @@ void test_flat_map() {
constexpr auto simple_truth = [](const auto&) { return true; };

flat_map<int, int> fm;
fm.emplace(1, 1);
fm.emplace(1, 2);
fm.emplace(42, 172);
fm.emplace(42, 729);
assert(fm.size() == 1);
erase_if(fm, simple_truth);
assert(erase_if(fm, simple_truth) == 1);
assert(fm.empty());

flat_multimap<int, int> fmm;
fmm.emplace(1, 1);
fmm.emplace(1, 2);
fmm.emplace(42, 172);
fmm.emplace(42, 729);
assert(fmm.size() == 2);
erase_if(fmm, simple_truth);
assert(erase_if(fmm, simple_truth) == 2);
assert(fmm.empty());
}
#endif // TEST_STANDARD >= 23
Expand Down
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