// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___RANGES_TRANSFORM_VIEW_H
#define _LIBCPP___RANGES_TRANSFORM_VIEW_H
#include <__compare/three_way_comparable.h>
#include <__concepts/constructible.h>
#include <__concepts/convertible_to.h>
#include <__concepts/copyable.h>
#include <__concepts/derived_from.h>
#include <__concepts/equality_comparable.h>
#include <__concepts/invocable.h>
#include <__config>
#include <__functional/bind_back.h>
#include <__functional/invoke.h>
#include <__functional/perfect_forward.h>
#include <__iterator/concepts.h>
#include <__iterator/iterator_traits.h>
#include <__memory/addressof.h>
#include <__ranges/access.h>
#include <__ranges/all.h>
#include <__ranges/concepts.h>
#include <__ranges/empty.h>
#include <__ranges/movable_box.h>
#include <__ranges/range_adaptor.h>
#include <__ranges/size.h>
#include <__ranges/view_interface.h>
#include <__type_traits/conditional.h>
#include <__type_traits/decay.h>
#include <__type_traits/invoke.h>
#include <__type_traits/is_nothrow_constructible.h>
#include <__type_traits/is_object.h>
#include <__type_traits/is_reference.h>
#include <__type_traits/maybe_const.h>
#include <__type_traits/remove_cvref.h>
#include <__utility/forward.h>
#include <__utility/in_place.h>
#include <__utility/move.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 20
namespace ranges {
template <class _Fn, class _View>
concept __regular_invocable_with_range_ref = regular_invocable<_Fn, range_reference_t<_View>>;
template <class _View, class _Fn>
concept __transform_view_constraints =
view<_View> && is_object_v<_Fn> && regular_invocable<_Fn&, range_reference_t<_View>> &&
__can_reference<invoke_result_t<_Fn&, range_reference_t<_View>>>;
# if _LIBCPP_STD_VER >= 23
template <input_range _View, move_constructible _Fn>
# else
template <input_range _View, copy_constructible _Fn>
# endif
requires __transform_view_constraints<_View, _Fn>
class _LIBCPP_ABI_LLVM18_NO_UNIQUE_ADDRESS transform_view : public view_interface<transform_view<_View, _Fn>> {
template <bool>
class __iterator;
template <bool>
class __sentinel;
_LIBCPP_NO_UNIQUE_ADDRESS __movable_box<_Fn> __func_;
_LIBCPP_NO_UNIQUE_ADDRESS _View __base_ = _View();
public:
_LIBCPP_HIDE_FROM_ABI transform_view()
requires default_initializable<_View> && default_initializable<_Fn>
= default;
_LIBCPP_HIDE_FROM_ABI constexpr _LIBCPP_EXPLICIT_SINCE_CXX23 transform_view(_View __base, _Fn __func)
: __func_(std::in_place, std::move(__func)), __base_(std::move(__base)) {}
_LIBCPP_HIDE_FROM_ABI constexpr _View base() const&
requires copy_constructible<_View>
{
return __base_;
}
_LIBCPP_HIDE_FROM_ABI constexpr _View base() && { return std::move(__base_); }
_LIBCPP_HIDE_FROM_ABI constexpr __iterator<false> begin() { return __iterator<false>{*this, ranges::begin(__base_)}; }
_LIBCPP_HIDE_FROM_ABI constexpr __iterator<true> begin() const
requires range<const _View> && __regular_invocable_with_range_ref<const _Fn&, const _View>
{
return __iterator<true>(*this, ranges::begin(__base_));
}
_LIBCPP_HIDE_FROM_ABI constexpr __sentinel<false> end() { return __sentinel<false>(ranges::end(__base_)); }
_LIBCPP_HIDE_FROM_ABI constexpr __iterator<false> end()
requires common_range<_View>
{
return __iterator<false>(*this, ranges::end(__base_));
}
_LIBCPP_HIDE_FROM_ABI constexpr __sentinel<true> end() const
requires range<const _View> && __regular_invocable_with_range_ref<const _Fn&, const _View>
{
return __sentinel<true>(ranges::end(__base_));
}
_LIBCPP_HIDE_FROM_ABI constexpr __iterator<true> end() const
requires common_range<const _View> && __regular_invocable_with_range_ref<const _Fn&, const _View>
{
return __iterator<true>(*this, ranges::end(__base_));
}
_LIBCPP_HIDE_FROM_ABI constexpr auto size()
requires sized_range<_View>
{
return ranges::size(__base_);
}
_LIBCPP_HIDE_FROM_ABI constexpr auto size() const
requires sized_range<const _View>
{
return ranges::size(__base_);
}
};
template <class _Range, class _Fn>
transform_view(_Range&&, _Fn) -> transform_view<views::all_t<_Range>, _Fn>;
template <class _View>
struct __transform_view_iterator_concept {
using type = input_iterator_tag;
};
template <random_access_range _View>
struct __transform_view_iterator_concept<_View> {
using type = random_access_iterator_tag;
};
template <bidirectional_range _View>
struct __transform_view_iterator_concept<_View> {
using type = bidirectional_iterator_tag;
};
template <forward_range _View>
struct __transform_view_iterator_concept<_View> {
using type = forward_iterator_tag;
};
template <class, class>
struct __transform_view_iterator_category_base {};
template <forward_range _View, class _Fn>
struct __transform_view_iterator_category_base<_View, _Fn> {
using _Cat = typename iterator_traits<iterator_t<_View>>::iterator_category;
using iterator_category =
conditional_t< is_reference_v<invoke_result_t<_Fn&, range_reference_t<_View>>>,
conditional_t< derived_from<_Cat, contiguous_iterator_tag>, random_access_iterator_tag, _Cat >,
input_iterator_tag >;
};
# if _LIBCPP_STD_VER >= 23
template <input_range _View, move_constructible _Fn>
# else
template <input_range _View, copy_constructible _Fn>
# endif
requires __transform_view_constraints<_View, _Fn>
template <bool _Const>
class transform_view<_View, _Fn>::__iterator
: public __transform_view_iterator_category_base<_View, __maybe_const<_Const, _Fn>> {
using _Parent = __maybe_const<_Const, transform_view>;
using _Base = __maybe_const<_Const, _View>;
_Parent* __parent_ = nullptr;
template <bool>
friend class transform_view<_View, _Fn>::__iterator;
template <bool>
friend class transform_view<_View, _Fn>::__sentinel;
public:
iterator_t<_Base> __current_ = iterator_t<_Base>();
using iterator_concept = typename __transform_view_iterator_concept<_View>::type;
using value_type = remove_cvref_t<invoke_result_t<__maybe_const<_Const, _Fn>&, range_reference_t<_Base>>>;
using difference_type = range_difference_t<_Base>;
_LIBCPP_HIDE_FROM_ABI __iterator()
requires default_initializable<iterator_t<_Base>>
= default;
_LIBCPP_HIDE_FROM_ABI constexpr __iterator(_Parent& __parent, iterator_t<_Base> __current)
: __parent_(std::addressof(__parent)), __current_(std::move(__current)) {}
// Note: `__i` should always be `__iterator<false>`, but directly using
// `__iterator<false>` is ill-formed when `_Const` is false
// (see http://wg21.link/class.copy.ctor#5).
_LIBCPP_HIDE_FROM_ABI constexpr __iterator(__iterator<!_Const> __i)
requires _Const && convertible_to<iterator_t<_View>, iterator_t<_Base>>
: __parent_(__i.__parent_), __current_(std::move(__i.__current_)) {}
_LIBCPP_HIDE_FROM_ABI constexpr const iterator_t<_Base>& base() const& noexcept { return __current_; }
_LIBCPP_HIDE_FROM_ABI constexpr iterator_t<_Base> base() && { return std::move(__current_); }
_LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) operator*() const
noexcept(noexcept(std::invoke(*__parent_->__func_, *__current_))) {
return std::invoke(*__parent_->__func_, *__current_);
}
_LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator++() {
++__current_;
return *this;
}
_LIBCPP_HIDE_FROM_ABI constexpr void operator++(int) { ++__current_; }
_LIBCPP_HIDE_FROM_ABI constexpr __iterator operator++(int)
requires forward_range<_Base>
{
auto __tmp = *this;
++*this;
return __tmp;
}
_LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator--()
requires bidirectional_range<_Base>
{
--__current_;
return *this;
}
_LIBCPP_HIDE_FROM_ABI constexpr __iterator operator--(int)
requires bidirectional_range<_Base>
{
auto __tmp = *this;
--*this;
return __tmp;
}
_LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator+=(difference_type __n)
requires random_access_range<_Base>
{
__current_ += __n;
return *this;
}
_LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator-=(difference_type __n)
requires random_access_range<_Base>
{
__current_ -= __n;
return *this;
}
_LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) operator[](difference_type __n) const
noexcept(noexcept(std::invoke(*__parent_->__func_, __current_[__n])))
requires random_access_range<_Base>
{
return std::invoke(*__parent_->__func_, __current_[__n]);
}
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator& __x, const __iterator& __y)
requires equality_comparable<iterator_t<_Base>>
{
return __x.__current_ == __y.__current_;
}
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<(const __iterator& __x, const __iterator& __y)
requires random_access_range<_Base>
{
return __x.__current_ < __y.__current_;
}
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>(const __iterator& __x, const __iterator& __y)
requires random_access_range<_Base>
{
return __x.__current_ > __y.__current_;
}
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<=(const __iterator& __x, const __iterator& __y)
requires random_access_range<_Base>
{
return __x.__current_ <= __y.__current_;
}
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>=(const __iterator& __x, const __iterator& __y)
requires random_access_range<_Base>
{
return __x.__current_ >= __y.__current_;
}
_LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<=>(const __iterator& __x, const __iterator& __y)
requires random_access_range<_Base> && three_way_comparable<iterator_t<_Base>>
{
return __x.__current_ <=> __y.__current_;
}
_LIBCPP_HIDE_FROM_ABI friend constexpr __iterator operator+(__iterator __i, difference_type __n)
requires random_access_range<_Base>
{
return __iterator{*__i.__parent_, __i.__current_ + __n};
}
_LIBCPP_HIDE_FROM_ABI friend constexpr __iterator operator+(difference_type __n, __iterator __i)
requires random_access_range<_Base>
{
return __iterator{*__i.__parent_, __i.__current_ + __n};
}
_LIBCPP_HIDE_FROM_ABI friend constexpr __iterator operator-(__iterator __i, difference_type __n)
requires random_access_range<_Base>
{
return __iterator{*__i.__parent_, __i.__current_ - __n};
}
_LIBCPP_HIDE_FROM_ABI friend constexpr difference_type operator-(const __iterator& __x, const __iterator& __y)
requires sized_sentinel_for<iterator_t<_Base>, iterator_t<_Base>>
{
return __x.__current_ - __y.__current_;
}
};
# if _LIBCPP_STD_VER >= 23
template <input_range _View, move_constructible _Fn>
# else
template <input_range _View, copy_constructible _Fn>
# endif
requires __transform_view_constraints<_View, _Fn>
template <bool _Const>
class transform_view<_View, _Fn>::__sentinel {
using _Parent = __maybe_const<_Const, transform_view>;
using _Base = __maybe_const<_Const, _View>;
sentinel_t<_Base> __end_ = sentinel_t<_Base>();
template <bool>
friend class transform_view<_View, _Fn>::__iterator;
template <bool>
friend class transform_view<_View, _Fn>::__sentinel;
public:
_LIBCPP_HIDE_FROM_ABI __sentinel() = default;
_LIBCPP_HIDE_FROM_ABI constexpr explicit __sentinel(sentinel_t<_Base> __end) : __end_(__end) {}
// Note: `__i` should always be `__sentinel<false>`, but directly using
// `__sentinel<false>` is ill-formed when `_Const` is false
// (see http://wg21.link/class.copy.ctor#5).
_LIBCPP_HIDE_FROM_ABI constexpr __sentinel(__sentinel<!_Const> __i)
requires _Const && convertible_to<sentinel_t<_View>, sentinel_t<_Base>>
: __end_(std::move(__i.__end_)) {}
_LIBCPP_HIDE_FROM_ABI constexpr sentinel_t<_Base> base() const { return __end_; }
template <bool _OtherConst>
requires sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>>
_LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator<_OtherConst>& __x, const __sentinel& __y) {
return __x.__current_ == __y.__end_;
}
template <bool _OtherConst>
requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>>
_LIBCPP_HIDE_FROM_ABI friend constexpr range_difference_t<__maybe_const<_OtherConst, _View>>
operator-(const __iterator<_OtherConst>& __x, const __sentinel& __y) {
return __x.__current_ - __y.__end_;
}
template <bool _OtherConst>
requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>>
_LIBCPP_HIDE_FROM_ABI friend constexpr range_difference_t<__maybe_const<_OtherConst, _View>>
operator-(const __sentinel& __x, const __iterator<_OtherConst>& __y) {
return __x.__end_ - __y.__current_;
}
};
namespace views {
namespace __transform {
struct __fn {
template <class _Range, class _Fn>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Range&& __range, _Fn&& __f) const
noexcept(noexcept(transform_view(std::forward<_Range>(__range), std::forward<_Fn>(__f))))
-> decltype(transform_view(std::forward<_Range>(__range), std::forward<_Fn>(__f))) {
return transform_view(std::forward<_Range>(__range), std::forward<_Fn>(__f));
}
template <class _Fn>
requires constructible_from<decay_t<_Fn>, _Fn>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Fn&& __f) const
noexcept(is_nothrow_constructible_v<decay_t<_Fn>, _Fn>) {
return __pipeable(std::__bind_back(*this, std::forward<_Fn>(__f)));
}
};
} // namespace __transform
inline namespace __cpo {
inline constexpr auto transform = __transform::__fn{};
} // namespace __cpo
} // namespace views
} // namespace ranges
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___RANGES_TRANSFORM_VIEW_H
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