zig/lib/libcxx/include/__ranges/view_interface.h
2023-01-26 16:36:13 -07:00

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5.2 KiB
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// -*- 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_VIEW_INTERFACE_H
#define _LIBCPP___RANGES_VIEW_INTERFACE_H
#include <__assert>
#include <__concepts/derived_from.h>
#include <__concepts/same_as.h>
#include <__config>
#include <__iterator/concepts.h>
#include <__iterator/iterator_traits.h>
#include <__iterator/prev.h>
#include <__memory/pointer_traits.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__ranges/empty.h>
#include <__type_traits/is_class.h>
#include <__type_traits/make_unsigned.h>
#include <__type_traits/remove_cv.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 17
namespace ranges {
template<class _Derived>
requires is_class_v<_Derived> && same_as<_Derived, remove_cv_t<_Derived>>
class view_interface {
_LIBCPP_HIDE_FROM_ABI
constexpr _Derived& __derived() noexcept {
static_assert(sizeof(_Derived) && derived_from<_Derived, view_interface> && view<_Derived>);
return static_cast<_Derived&>(*this);
}
_LIBCPP_HIDE_FROM_ABI
constexpr _Derived const& __derived() const noexcept {
static_assert(sizeof(_Derived) && derived_from<_Derived, view_interface> && view<_Derived>);
return static_cast<_Derived const&>(*this);
}
public:
template<class _D2 = _Derived>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty()
requires forward_range<_D2>
{
return ranges::begin(__derived()) == ranges::end(__derived());
}
template<class _D2 = _Derived>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty() const
requires forward_range<const _D2>
{
return ranges::begin(__derived()) == ranges::end(__derived());
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr explicit operator bool()
requires requires (_D2& __t) { ranges::empty(__t); }
{
return !ranges::empty(__derived());
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr explicit operator bool() const
requires requires (const _D2& __t) { ranges::empty(__t); }
{
return !ranges::empty(__derived());
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr auto data()
requires contiguous_iterator<iterator_t<_D2>>
{
return std::to_address(ranges::begin(__derived()));
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr auto data() const
requires range<const _D2> && contiguous_iterator<iterator_t<const _D2>>
{
return std::to_address(ranges::begin(__derived()));
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr auto size()
requires forward_range<_D2> && sized_sentinel_for<sentinel_t<_D2>, iterator_t<_D2>>
{
return std::__to_unsigned_like(ranges::end(__derived()) - ranges::begin(__derived()));
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr auto size() const
requires forward_range<const _D2> && sized_sentinel_for<sentinel_t<const _D2>, iterator_t<const _D2>>
{
return std::__to_unsigned_like(ranges::end(__derived()) - ranges::begin(__derived()));
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr decltype(auto) front()
requires forward_range<_D2>
{
_LIBCPP_ASSERT(!empty(),
"Precondition `!empty()` not satisfied. `.front()` called on an empty view.");
return *ranges::begin(__derived());
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr decltype(auto) front() const
requires forward_range<const _D2>
{
_LIBCPP_ASSERT(!empty(),
"Precondition `!empty()` not satisfied. `.front()` called on an empty view.");
return *ranges::begin(__derived());
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr decltype(auto) back()
requires bidirectional_range<_D2> && common_range<_D2>
{
_LIBCPP_ASSERT(!empty(),
"Precondition `!empty()` not satisfied. `.back()` called on an empty view.");
return *ranges::prev(ranges::end(__derived()));
}
template<class _D2 = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr decltype(auto) back() const
requires bidirectional_range<const _D2> && common_range<const _D2>
{
_LIBCPP_ASSERT(!empty(),
"Precondition `!empty()` not satisfied. `.back()` called on an empty view.");
return *ranges::prev(ranges::end(__derived()));
}
template<random_access_range _RARange = _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr decltype(auto) operator[](range_difference_t<_RARange> __index)
{
return ranges::begin(__derived())[__index];
}
template<random_access_range _RARange = const _Derived>
_LIBCPP_HIDE_FROM_ABI
constexpr decltype(auto) operator[](range_difference_t<_RARange> __index) const
{
return ranges::begin(__derived())[__index];
}
};
} // namespace ranges
#endif // _LIBCPP_STD_VER > 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___RANGES_VIEW_INTERFACE_H