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[libc++] Remove unnecessary static_casts in std::forward_list #130310

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[libc++] Remove unnecessary static_casts in std::forward_list #130310

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d3fa07b
Remove unnecessary static_casts in std::forward_list
winner245 Mar 7, 2025
97a24fb
Inline the casts
winner245 Mar 8, 2025
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100 changes: 41 additions & 59 deletions libcxx/include/forward_list
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Original file line number Diff line number Diff line change
Expand Up @@ -294,10 +294,6 @@ struct __forward_node_traits {
"is being broken between LLVM 19 and LLVM 20. If you don't care about your ABI being broken, define "
"the _LIBCPP_ABI_FORWARD_LIST_REMOVE_NODE_POINTER_UB macro to silence this diagnostic.");
# endif

_LIBCPP_HIDE_FROM_ABI static __begin_node_pointer __as_iter_node(__node_pointer __p) {
return static_cast<__begin_node_pointer>(static_cast<__void_pointer>(__p));
}
};

template <class _NodePtr>
Expand All @@ -309,10 +305,6 @@ struct __forward_begin_node {

_LIBCPP_HIDE_FROM_ABI __forward_begin_node() : __next_(nullptr) {}
_LIBCPP_HIDE_FROM_ABI explicit __forward_begin_node(pointer __n) : __next_(__n) {}

_LIBCPP_HIDE_FROM_ABI __begin_node_pointer __next_as_begin() const {
return static_cast<__begin_node_pointer>(__next_);
}
};

template <class _Tp, class _VoidPtr>
Expand Down Expand Up @@ -363,19 +355,12 @@ class _LIBCPP_TEMPLATE_VIS __forward_list_iterator {

__begin_node_pointer __ptr_;

_LIBCPP_HIDE_FROM_ABI __begin_node_pointer __get_begin() const {
return static_cast<__begin_node_pointer>(static_cast<__void_pointer>(__ptr_));
}
_LIBCPP_HIDE_FROM_ABI __node_pointer __get_unsafe_node_pointer() const {
return static_cast<__node_pointer>(static_cast<__void_pointer>(__ptr_));
}

_LIBCPP_HIDE_FROM_ABI explicit __forward_list_iterator(nullptr_t) _NOEXCEPT : __ptr_(nullptr) {}

_LIBCPP_HIDE_FROM_ABI explicit __forward_list_iterator(__begin_node_pointer __p) _NOEXCEPT : __ptr_(__p) {}

_LIBCPP_HIDE_FROM_ABI explicit __forward_list_iterator(__node_pointer __p) _NOEXCEPT
: __ptr_(__traits::__as_iter_node(__p)) {}
: __ptr_(static_cast<__begin_node_pointer>(__p)) {}

template <class, class>
friend class _LIBCPP_TEMPLATE_VIS forward_list;
Expand All @@ -391,13 +376,13 @@ public:

_LIBCPP_HIDE_FROM_ABI __forward_list_iterator() _NOEXCEPT : __ptr_(nullptr) {}

_LIBCPP_HIDE_FROM_ABI reference operator*() const { return __get_unsafe_node_pointer()->__get_value(); }
_LIBCPP_HIDE_FROM_ABI reference operator*() const { return static_cast<__node_pointer>(__ptr_)->__get_value(); }
_LIBCPP_HIDE_FROM_ABI pointer operator->() const {
return pointer_traits<pointer>::pointer_to(__get_unsafe_node_pointer()->__get_value());
return pointer_traits<pointer>::pointer_to(static_cast<__node_pointer>(__ptr_)->__get_value());
}

_LIBCPP_HIDE_FROM_ABI __forward_list_iterator& operator++() {
__ptr_ = __traits::__as_iter_node(__ptr_->__next_);
__ptr_ = static_cast<__begin_node_pointer>(__ptr_->__next_);
return *this;
}
_LIBCPP_HIDE_FROM_ABI __forward_list_iterator operator++(int) {
Expand Down Expand Up @@ -427,19 +412,12 @@ class _LIBCPP_TEMPLATE_VIS __forward_list_const_iterator {

__begin_node_pointer __ptr_;

_LIBCPP_HIDE_FROM_ABI __begin_node_pointer __get_begin() const {
return static_cast<__begin_node_pointer>(static_cast<__void_pointer>(__ptr_));
}
_LIBCPP_HIDE_FROM_ABI __node_pointer __get_unsafe_node_pointer() const {
return static_cast<__node_pointer>(static_cast<__void_pointer>(__ptr_));
}

_LIBCPP_HIDE_FROM_ABI explicit __forward_list_const_iterator(nullptr_t) _NOEXCEPT : __ptr_(nullptr) {}

_LIBCPP_HIDE_FROM_ABI explicit __forward_list_const_iterator(__begin_node_pointer __p) _NOEXCEPT : __ptr_(__p) {}

_LIBCPP_HIDE_FROM_ABI explicit __forward_list_const_iterator(__node_pointer __p) _NOEXCEPT
: __ptr_(__traits::__as_iter_node(__p)) {}
: __ptr_(static_cast<__begin_node_pointer>(__p)) {}

template <class, class>
friend class forward_list;
Expand All @@ -455,13 +433,13 @@ public:
_LIBCPP_HIDE_FROM_ABI __forward_list_const_iterator(__forward_list_iterator<__node_pointer> __p) _NOEXCEPT
: __ptr_(__p.__ptr_) {}

_LIBCPP_HIDE_FROM_ABI reference operator*() const { return __get_unsafe_node_pointer()->__get_value(); }
_LIBCPP_HIDE_FROM_ABI reference operator*() const { return static_cast<__node_pointer>(__ptr_)->__get_value(); }
_LIBCPP_HIDE_FROM_ABI pointer operator->() const {
return pointer_traits<pointer>::pointer_to(__get_unsafe_node_pointer()->__get_value());
return pointer_traits<pointer>::pointer_to(static_cast<__node_pointer>(__ptr_)->__get_value());
}

_LIBCPP_HIDE_FROM_ABI __forward_list_const_iterator& operator++() {
__ptr_ = __traits::__as_iter_node(__ptr_->__next_);
__ptr_ = static_cast<__begin_node_pointer>(__ptr_->__next_);
return *this;
}
_LIBCPP_HIDE_FROM_ABI __forward_list_const_iterator operator++(int) {
Expand Down Expand Up @@ -911,7 +889,8 @@ inline forward_list<_Tp, _Alloc>::forward_list(const allocator_type& __a) : __ba
template <class _Tp, class _Alloc>
forward_list<_Tp, _Alloc>::forward_list(size_type __n) {
if (__n > 0) {
for (__begin_node_pointer __p = __base::__before_begin(); __n > 0; --__n, __p = __p->__next_as_begin()) {
for (__begin_node_pointer __p = __base::__before_begin(); __n > 0;
--__n, __p = static_cast<__begin_node_pointer>(__p->__next_)) {
__p->__next_ = this->__create_node(/* next = */ nullptr);
}
}
Expand All @@ -921,7 +900,8 @@ forward_list<_Tp, _Alloc>::forward_list(size_type __n) {
template <class _Tp, class _Alloc>
forward_list<_Tp, _Alloc>::forward_list(size_type __n, const allocator_type& __base_alloc) : __base(__base_alloc) {
if (__n > 0) {
for (__begin_node_pointer __p = __base::__before_begin(); __n > 0; --__n, __p = __p->__next_as_begin()) {
for (__begin_node_pointer __p = __base::__before_begin(); __n > 0;
--__n, __p = static_cast<__begin_node_pointer>(__p->__next_)) {
__p->__next_ = this->__create_node(/* next = */ nullptr);
}
}
Expand Down Expand Up @@ -1105,15 +1085,15 @@ template <class _Tp, class _Alloc>
template <class... _Args>
typename forward_list<_Tp, _Alloc>::iterator
forward_list<_Tp, _Alloc>::emplace_after(const_iterator __p, _Args&&... __args) {
__begin_node_pointer const __r = __p.__get_begin();
__begin_node_pointer const __r = __p.__ptr_;
__r->__next_ = this->__create_node(/* next = */ __r->__next_, std::forward<_Args>(__args)...);
return iterator(__r->__next_);
}

template <class _Tp, class _Alloc>
typename forward_list<_Tp, _Alloc>::iterator
forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, value_type&& __v) {
__begin_node_pointer const __r = __p.__get_begin();
__begin_node_pointer const __r = __p.__ptr_;
__r->__next_ = this->__create_node(/* next = */ __r->__next_, std::move(__v));
return iterator(__r->__next_);
}
Expand All @@ -1123,15 +1103,15 @@ forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, value_type&& __v) {
template <class _Tp, class _Alloc>
typename forward_list<_Tp, _Alloc>::iterator
forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, const value_type& __v) {
__begin_node_pointer const __r = __p.__get_begin();
__begin_node_pointer const __r = __p.__ptr_;
__r->__next_ = this->__create_node(/* next = */ __r->__next_, __v);
return iterator(__r->__next_);
}

template <class _Tp, class _Alloc>
typename forward_list<_Tp, _Alloc>::iterator
forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, size_type __n, const value_type& __v) {
__begin_node_pointer __r = __p.__get_begin();
__begin_node_pointer __r = __p.__ptr_;
if (__n > 0) {
__node_pointer __first = this->__create_node(/* next = */ nullptr, __v);
__node_pointer __last = __first;
Expand Down Expand Up @@ -1169,7 +1149,7 @@ template <class _Tp, class _Alloc>
template <class _InputIterator, class _Sentinel>
_LIBCPP_HIDE_FROM_ABI typename forward_list<_Tp, _Alloc>::iterator
forward_list<_Tp, _Alloc>::__insert_after_with_sentinel(const_iterator __p, _InputIterator __f, _Sentinel __l) {
__begin_node_pointer __r = __p.__get_begin();
__begin_node_pointer __r = __p.__ptr_;

if (__f != __l) {
__node_pointer __first = this->__create_node(/* next = */ nullptr, *__f);
Expand Down Expand Up @@ -1202,7 +1182,7 @@ forward_list<_Tp, _Alloc>::__insert_after_with_sentinel(const_iterator __p, _Inp

template <class _Tp, class _Alloc>
typename forward_list<_Tp, _Alloc>::iterator forward_list<_Tp, _Alloc>::erase_after(const_iterator __f) {
__begin_node_pointer __p = __f.__get_begin();
__begin_node_pointer __p = __f.__ptr_;
__node_pointer __n = __p->__next_;
__p->__next_ = __n->__next_;
this->__delete_node(__n);
Expand All @@ -1212,9 +1192,9 @@ typename forward_list<_Tp, _Alloc>::iterator forward_list<_Tp, _Alloc>::erase_af
template <class _Tp, class _Alloc>
typename forward_list<_Tp, _Alloc>::iterator
forward_list<_Tp, _Alloc>::erase_after(const_iterator __f, const_iterator __l) {
__node_pointer __e = __l.__get_unsafe_node_pointer();
__node_pointer __e = static_cast<__node_pointer>(__l.__ptr_);
if (__f != __l) {
__begin_node_pointer __bp = __f.__get_begin();
__begin_node_pointer __bp = __f.__ptr_;

__node_pointer __n = __bp->__next_;
if (__n != __e) {
Expand Down Expand Up @@ -1242,7 +1222,8 @@ void forward_list<_Tp, _Alloc>::resize(size_type __n) {
else {
__n -= __sz;
if (__n > 0) {
for (__begin_node_pointer __ptr = __p.__get_begin(); __n > 0; --__n, __ptr = __ptr->__next_as_begin()) {
for (__begin_node_pointer __ptr = __p.__ptr_; __n > 0;
--__n, __ptr = static_cast<__begin_node_pointer>(__ptr->__next_)) {
__ptr->__next_ = this->__create_node(/* next = */ nullptr);
}
}
Expand All @@ -1262,7 +1243,8 @@ void forward_list<_Tp, _Alloc>::resize(size_type __n, const value_type& __v) {
else {
__n -= __sz;
if (__n > 0) {
for (__begin_node_pointer __ptr = __p.__get_begin(); __n > 0; --__n, __ptr = __ptr->__next_as_begin()) {
for (__begin_node_pointer __ptr = __p.__ptr_; __n > 0;
--__n, __ptr = static_cast<__begin_node_pointer>(__ptr->__next_)) {
__ptr->__next_ = this->__create_node(/* next = */ nullptr, __v);
}
}
Expand All @@ -1272,13 +1254,13 @@ void forward_list<_Tp, _Alloc>::resize(size_type __n, const value_type& __v) {
template <class _Tp, class _Alloc>
void forward_list<_Tp, _Alloc>::splice_after(const_iterator __p, forward_list& __x) {
if (!__x.empty()) {
if (__p.__get_begin()->__next_ != nullptr) {
if (__p.__ptr_->__next_ != nullptr) {
const_iterator __lm1 = __x.before_begin();
while (__lm1.__get_begin()->__next_ != nullptr)
while (__lm1.__ptr_->__next_ != nullptr)
++__lm1;
__lm1.__get_begin()->__next_ = __p.__get_begin()->__next_;
__lm1.__ptr_->__next_ = __p.__ptr_->__next_;
}
__p.__get_begin()->__next_ = __x.__before_begin()->__next_;
__p.__ptr_->__next_ = __x.__before_begin()->__next_;
__x.__before_begin()->__next_ = nullptr;
}
}
Expand All @@ -1287,9 +1269,9 @@ template <class _Tp, class _Alloc>
void forward_list<_Tp, _Alloc>::splice_after(const_iterator __p, forward_list& /*__other*/, const_iterator __i) {
const_iterator __lm1 = std::next(__i);
if (__p != __i && __p != __lm1) {
__i.__get_begin()->__next_ = __lm1.__get_begin()->__next_;
__lm1.__get_begin()->__next_ = __p.__get_begin()->__next_;
__p.__get_begin()->__next_ = __lm1.__get_unsafe_node_pointer();
__i.__ptr_->__next_ = __lm1.__ptr_->__next_;
__lm1.__ptr_->__next_ = __p.__ptr_->__next_;
__p.__ptr_->__next_ = static_cast<__node_pointer>(__lm1.__ptr_);
}
}

Expand All @@ -1298,12 +1280,12 @@ void forward_list<_Tp, _Alloc>::splice_after(
const_iterator __p, forward_list& /*__other*/, const_iterator __f, const_iterator __l) {
if (__f != __l && __p != __f) {
const_iterator __lm1 = __f;
while (__lm1.__get_begin()->__next_ != __l.__get_begin())
while (__lm1.__ptr_->__next_ != __l.__ptr_)
++__lm1;
if (__f != __lm1) {
__lm1.__get_begin()->__next_ = __p.__get_begin()->__next_;
__p.__get_begin()->__next_ = __f.__get_begin()->__next_;
__f.__get_begin()->__next_ = __l.__get_unsafe_node_pointer();
__lm1.__ptr_->__next_ = __p.__ptr_->__next_;
__p.__ptr_->__next_ = __f.__ptr_->__next_;
__f.__ptr_->__next_ = static_cast<__node_pointer>(__l.__ptr_);
}
}
}
Expand All @@ -1330,8 +1312,8 @@ typename forward_list<_Tp, _Alloc>::__remove_return_type forward_list<_Tp, _Allo
forward_list<_Tp, _Alloc> __deleted_nodes(get_allocator()); // collect the nodes we're removing
typename forward_list<_Tp, _Alloc>::size_type __count_removed = 0;
const iterator __e = end();
for (iterator __i = before_begin(); __i.__get_begin()->__next_ != nullptr;) {
if (__i.__get_begin()->__next_->__get_value() == __v) {
for (iterator __i = before_begin(); __i.__ptr_->__next_ != nullptr;) {
if (__i.__ptr_->__next_->__get_value() == __v) {
++__count_removed;
iterator __j = std::next(__i, 2);
for (; __j != __e && *__j == __v; ++__j)
Expand All @@ -1353,8 +1335,8 @@ typename forward_list<_Tp, _Alloc>::__remove_return_type forward_list<_Tp, _Allo
forward_list<_Tp, _Alloc> __deleted_nodes(get_allocator()); // collect the nodes we're removing
typename forward_list<_Tp, _Alloc>::size_type __count_removed = 0;
const iterator __e = end();
for (iterator __i = before_begin(); __i.__get_begin()->__next_ != nullptr;) {
if (__pred(__i.__get_begin()->__next_->__get_value())) {
for (iterator __i = before_begin(); __i.__ptr_->__next_ != nullptr;) {
if (__pred(__i.__ptr_->__next_->__get_value())) {
++__count_removed;
iterator __j = std::next(__i, 2);
for (; __j != __e && __pred(*__j); ++__j)
Expand All @@ -1380,7 +1362,7 @@ forward_list<_Tp, _Alloc>::unique(_BinaryPredicate __binary_pred) {
iterator __j = std::next(__i);
for (; __j != __e && __binary_pred(*__i, *__j); ++__j)
++__count_removed;
if (__i.__get_begin()->__next_ != __j.__get_unsafe_node_pointer())
if (__i.__ptr_->__next_ != static_cast<__node_pointer>(__j.__ptr_))
__deleted_nodes.splice_after(__deleted_nodes.before_begin(), *this, __i, __j);
__i = __j;
}
Expand Down Expand Up @@ -1460,7 +1442,7 @@ forward_list<_Tp, _Alloc>::__sort(__node_pointer __f1, difference_type __sz, _Co
}
difference_type __sz1 = __sz / 2;
difference_type __sz2 = __sz - __sz1;
__node_pointer __t = std::next(iterator(__f1), __sz1 - 1).__get_unsafe_node_pointer();
__node_pointer __t = static_cast<__node_pointer>(std::next(iterator(__f1), __sz1 - 1).__ptr_);
__node_pointer __f2 = __t->__next_;
__t->__next_ = nullptr;
return __merge(__sort(__f1, __sz1, __comp), __sort(__f2, __sz2, __comp), __comp);
Expand Down