STL/stl/inc/array

// array standard header

// Copyright (c) Microsoft Corporation.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#pragma once
#ifndef _ARRAY_
#define _ARRAY_
#include <yvals_core.h>
#if _STL_COMPILER_PREPROCESSOR
#include <algorithm>
#include <iterator>
#include <tuple>

#pragma pack(push, _CRT_PACKING)
#pragma warning(push, _STL_WARNING_LEVEL)
#pragma warning(disable : _STL_DISABLED_WARNINGS)
_STL_DISABLE_CLANG_WARNINGS
#pragma push_macro("new")
#undef new

_STD_BEGIN
// CLASS TEMPLATE array
template <class _Ty, size_t _Size>
class array { // fixed size array of values
public:
    using value_type      = _Ty;
    using size_type       = size_t;
    using difference_type = ptrdiff_t;
    using pointer         = _Ty*;
    using const_pointer   = const _Ty*;
    using reference       = _Ty&;
    using const_reference = const _Ty&;

    using iterator       = _Array_iterator<_Ty, _Size>;
    using const_iterator = _Array_const_iterator<_Ty, _Size>;

    using reverse_iterator       = _STD reverse_iterator<iterator>;
    using const_reverse_iterator = _STD reverse_iterator<const_iterator>;

#if _HAS_TR1_NAMESPACE
    _DEPRECATE_TR1_NAMESPACE void assign(const _Ty& _Value) {
        _STD fill_n(_Elems, _Size, _Value);
    }
#endif // _HAS_TR1_NAMESPACE

    void fill(const _Ty& _Value) {
        _STD fill_n(_Elems, _Size, _Value);
    }

    void swap(array& _Other) noexcept(_Is_nothrow_swappable<_Ty>::value) {
        _Swap_ranges_unchecked(_Elems, _Elems + _Size, _Other._Elems);
    }

    _NODISCARD _CONSTEXPR17 iterator begin() noexcept {
        return iterator(_Elems, 0);
    }

    _NODISCARD _CONSTEXPR17 const_iterator begin() const noexcept {
        return const_iterator(_Elems, 0);
    }

    _NODISCARD _CONSTEXPR17 iterator end() noexcept {
        return iterator(_Elems, _Size);
    }

    _NODISCARD _CONSTEXPR17 const_iterator end() const noexcept {
        return const_iterator(_Elems, _Size);
    }

    _NODISCARD _CONSTEXPR17 reverse_iterator rbegin() noexcept {
        return reverse_iterator(end());
    }

    _NODISCARD _CONSTEXPR17 const_reverse_iterator rbegin() const noexcept {
        return const_reverse_iterator(end());
    }

    _NODISCARD _CONSTEXPR17 reverse_iterator rend() noexcept {
        return reverse_iterator(begin());
    }

    _NODISCARD _CONSTEXPR17 const_reverse_iterator rend() const noexcept {
        return const_reverse_iterator(begin());
    }

    _NODISCARD _CONSTEXPR17 const_iterator cbegin() const noexcept {
        return begin();
    }

    _NODISCARD _CONSTEXPR17 const_iterator cend() const noexcept {
        return end();
    }

    _NODISCARD _CONSTEXPR17 const_reverse_iterator crbegin() const noexcept {
        return rbegin();
    }

    _NODISCARD _CONSTEXPR17 const_reverse_iterator crend() const noexcept {
        return rend();
    }

    _CONSTEXPR17 _Ty* _Unchecked_begin() noexcept {
        return _Elems;
    }

    _CONSTEXPR17 const _Ty* _Unchecked_begin() const noexcept {
        return _Elems;
    }

    _CONSTEXPR17 _Ty* _Unchecked_end() noexcept {
        return _Elems + _Size;
    }

    _CONSTEXPR17 const _Ty* _Unchecked_end() const noexcept {
        return _Elems + _Size;
    }

    _NODISCARD constexpr size_type size() const noexcept {
        return _Size;
    }

    _NODISCARD constexpr size_type max_size() const noexcept {
        return _Size;
    }

    _NODISCARD constexpr bool empty() const noexcept {
        return false;
    }

    _NODISCARD _CONSTEXPR17 reference at(size_type _Pos) {
        if (_Size <= _Pos) {
            _Xran();
        }

        return _Elems[_Pos];
    }

    _NODISCARD constexpr const_reference at(size_type _Pos) const {
        if (_Size <= _Pos) {
            _Xran();
        }

        return _Elems[_Pos];
    }

    _NODISCARD _CONSTEXPR17 reference operator[](_In_range_(0, _Size - 1) size_type _Pos) noexcept /* strengthened */ {
#if _CONTAINER_DEBUG_LEVEL > 0
        _STL_VERIFY(_Pos < _Size, "array subscript out of range");
#endif // _CONTAINER_DEBUG_LEVEL > 0

        return _Elems[_Pos];
    }

    _NODISCARD constexpr const_reference operator[](_In_range_(0, _Size - 1) size_type _Pos) const
        noexcept /* strengthened */ {
#if _CONTAINER_DEBUG_LEVEL > 0
        _STL_VERIFY(_Pos < _Size, "array subscript out of range");
#endif // _CONTAINER_DEBUG_LEVEL > 0

        return _Elems[_Pos];
    }

    _NODISCARD _CONSTEXPR17 reference front() noexcept /* strengthened */ {
        return _Elems[0];
    }

    _NODISCARD constexpr const_reference front() const noexcept /* strengthened */ {
        return _Elems[0];
    }

    _NODISCARD _CONSTEXPR17 reference back() noexcept /* strengthened */ {
        return _Elems[_Size - 1];
    }

    _NODISCARD constexpr const_reference back() const noexcept /* strengthened */ {
        return _Elems[_Size - 1];
    }

    _NODISCARD _CONSTEXPR17 _Ty* data() noexcept {
        return _Elems;
    }

    _NODISCARD _CONSTEXPR17 const _Ty* data() const noexcept {
        return _Elems;
    }

    [[noreturn]] void _Xran() const {
        _Xout_of_range("invalid array<T, N> subscript");
    }

    _Ty _Elems[_Size];
};

#if _HAS_CXX17
template <class _First, class... _Rest>
struct _Enforce_same {
    static_assert(conjunction_v<is_same<_First, _Rest>...>,
        "N4687 26.3.7.2 [array.cons]/2: "
        "Requires: (is_same_v<T, U> && ...) is true. Otherwise the program is ill-formed.");
    using type = _First;
};

template <class _First, class... _Rest>
array(_First, _Rest...)->array<typename _Enforce_same<_First, _Rest...>::type, 1 + sizeof...(_Rest)>;
#endif // _HAS_CXX17

template <class _Ty>
class array<_Ty, 0> {
public:
    using value_type      = _Ty;
    using size_type       = size_t;
    using difference_type = ptrdiff_t;
    using pointer         = _Ty*;
    using const_pointer   = const _Ty*;
    using reference       = _Ty&;
    using const_reference = const _Ty&;

    using iterator               = _Array_iterator<_Ty, 0>;
    using const_iterator         = _Array_const_iterator<_Ty, 0>;
    using reverse_iterator       = _STD reverse_iterator<iterator>;
    using const_reverse_iterator = _STD reverse_iterator<const_iterator>;

#if _HAS_TR1_NAMESPACE
    _DEPRECATE_TR1_NAMESPACE void assign(const _Ty&) {}
#endif // _HAS_TR1_NAMESPACE

    void fill(const _Ty&) {}

    void swap(array&) noexcept {}

    _NODISCARD _CONSTEXPR17 iterator begin() noexcept {
        return iterator{};
    }

    _NODISCARD _CONSTEXPR17 const_iterator begin() const noexcept {
        return const_iterator{};
    }

    _NODISCARD _CONSTEXPR17 iterator end() noexcept {
        return iterator{};
    }

    _NODISCARD _CONSTEXPR17 const_iterator end() const noexcept {
        return const_iterator{};
    }

    _NODISCARD _CONSTEXPR17 reverse_iterator rbegin() noexcept {
        return reverse_iterator(end());
    }

    _NODISCARD _CONSTEXPR17 const_reverse_iterator rbegin() const noexcept {
        return const_reverse_iterator(end());
    }

    _NODISCARD _CONSTEXPR17 reverse_iterator rend() noexcept {
        return reverse_iterator(begin());
    }

    _NODISCARD _CONSTEXPR17 const_reverse_iterator rend() const noexcept {
        return const_reverse_iterator(begin());
    }

    _NODISCARD _CONSTEXPR17 const_iterator cbegin() const noexcept {
        return begin();
    }

    _NODISCARD _CONSTEXPR17 const_iterator cend() const noexcept {
        return end();
    }

    _NODISCARD _CONSTEXPR17 const_reverse_iterator crbegin() const noexcept {
        return rbegin();
    }

    _NODISCARD _CONSTEXPR17 const_reverse_iterator crend() const noexcept {
        return rend();
    }

    _CONSTEXPR17 _Ty* _Unchecked_begin() noexcept {
        return nullptr;
    }

    _CONSTEXPR17 const _Ty* _Unchecked_begin() const noexcept {
        return nullptr;
    }

    _CONSTEXPR17 _Ty* _Unchecked_end() noexcept {
        return nullptr;
    }

    _CONSTEXPR17 const _Ty* _Unchecked_end() const noexcept {
        return nullptr;
    }

    _NODISCARD constexpr size_type size() const noexcept {
        return 0;
    }

    _NODISCARD constexpr size_type max_size() const noexcept {
        return 0;
    }

    _NODISCARD constexpr bool empty() const noexcept {
        return true;
    }

    [[noreturn]] reference at(size_type) {
        _Xran();
    }

    [[noreturn]] const_reference at(size_type) const {
        _Xran();
    }

    _NODISCARD reference operator[](size_type) noexcept /* strengthened */ {
#if _CONTAINER_DEBUG_LEVEL > 0
        _STL_REPORT_ERROR("array subscript out of range");
#endif // _CONTAINER_DEBUG_LEVEL > 0

        return _Elems[0];
    }

    _NODISCARD const_reference operator[](size_type) const noexcept /* strengthened */ {
#if _CONTAINER_DEBUG_LEVEL > 0
        _STL_REPORT_ERROR("array subscript out of range");
#endif // _CONTAINER_DEBUG_LEVEL > 0

        return _Elems[0];
    }

    _NODISCARD reference front() noexcept /* strengthened */ {
#if _CONTAINER_DEBUG_LEVEL > 0
        _STL_REPORT_ERROR("array<T, 0>::front() invalid");
#endif // _CONTAINER_DEBUG_LEVEL > 0

        return _Elems[0];
    }

    _NODISCARD const_reference front() const noexcept /* strengthened */ {
#if _CONTAINER_DEBUG_LEVEL > 0
        _STL_REPORT_ERROR("array<T, 0>::front() invalid");
#endif // _CONTAINER_DEBUG_LEVEL > 0

        return _Elems[0];
    }

    _NODISCARD reference back() noexcept /* strengthened */ {
#if _CONTAINER_DEBUG_LEVEL > 0
        _STL_REPORT_ERROR("array<T, 0>::back() invalid");
#endif // _CONTAINER_DEBUG_LEVEL > 0

        return _Elems[0];
    }

    _NODISCARD const_reference back() const noexcept /* strengthened */ {
#if _CONTAINER_DEBUG_LEVEL > 0
        _STL_REPORT_ERROR("array<T, 0>::back() invalid");
#endif // _CONTAINER_DEBUG_LEVEL > 0

        return _Elems[0];
    }

    _NODISCARD _CONSTEXPR17 _Ty* data() noexcept {
        return nullptr;
    }

    _NODISCARD _CONSTEXPR17 const _Ty* data() const noexcept {
        return nullptr;
    }

    [[noreturn]] void _Xran() const {
        _Xout_of_range("invalid array<T, 0> subscript");
    }

    _Ty _Elems[1];
};

template <class _Ty, size_t _Size, enable_if_t<_Size == 0 || _Is_swappable<_Ty>::value, int> = 0>
void swap(array<_Ty, _Size>& _Left, array<_Ty, _Size>& _Right) noexcept(noexcept(_Left.swap(_Right))) {
    return _Left.swap(_Right);
}

template <class _Ty, size_t _Size>
_NODISCARD bool operator==(const array<_Ty, _Size>& _Left, const array<_Ty, _Size>& _Right) {
    return _STD equal(_Left.begin(), _Left.end(), _Right.begin());
}

template <class _Ty, size_t _Size>
_NODISCARD bool operator!=(const array<_Ty, _Size>& _Left, const array<_Ty, _Size>& _Right) {
    return !(_Left == _Right);
}

template <class _Ty, size_t _Size>
_NODISCARD bool operator<(const array<_Ty, _Size>& _Left, const array<_Ty, _Size>& _Right) {
    return _STD lexicographical_compare(_Left.begin(), _Left.end(), _Right.begin(), _Right.end());
}

template <class _Ty, size_t _Size>
_NODISCARD bool operator>(const array<_Ty, _Size>& _Left, const array<_Ty, _Size>& _Right) {
    return _Right < _Left;
}

template <class _Ty, size_t _Size>
_NODISCARD bool operator<=(const array<_Ty, _Size>& _Left, const array<_Ty, _Size>& _Right) {
    return !(_Right < _Left);
}

template <class _Ty, size_t _Size>
_NODISCARD bool operator>=(const array<_Ty, _Size>& _Left, const array<_Ty, _Size>& _Right) {
    return !(_Left < _Right);
}

#if _HAS_CXX20
// FUNCTION TEMPLATE to_array
template <class _Ty, size_t _Size, size_t... _Idx>
_NODISCARD constexpr array<remove_cv_t<_Ty>, _Size> _To_array_lvalue_impl(
    _Ty (&_Array)[_Size], index_sequence<_Idx...>) {
    return {{_Array[_Idx]...}};
}

template <class _Ty, size_t _Size, size_t... _Idx>
_NODISCARD constexpr array<remove_cv_t<_Ty>, _Size> _To_array_rvalue_impl(
    _Ty(&&_Array)[_Size], index_sequence<_Idx...>) {
    return {{_STD move(_Array[_Idx])...}};
}

template <class _Ty, size_t _Size>
_NODISCARD constexpr array<remove_cv_t<_Ty>, _Size> to_array(_Ty (&_Array)[_Size]) {
    static_assert(!is_array_v<_Ty>, "N4830 [array.creation]/1: "
                                    "to_array does not accept multidimensional arrays.");
    static_assert(is_constructible_v<_Ty, _Ty&>, "N4830 [array.creation]/1: "
                                                 "to_array requires copy constructible elements.");
    return _To_array_lvalue_impl(_Array, make_index_sequence<_Size>{});
}

template <class _Ty, size_t _Size>
_NODISCARD constexpr array<remove_cv_t<_Ty>, _Size> to_array(_Ty(&&_Array)[_Size]) {
    static_assert(!is_array_v<_Ty>, "N4830 [array.creation]/4: "
                                    "to_array does not accept multidimensional arrays.");
    static_assert(is_move_constructible_v<_Ty>, "N4830 [array.creation]/4: "
                                                "to_array requires move constructible elements.");
    return _To_array_rvalue_impl(_STD move(_Array), make_index_sequence<_Size>{});
}
#endif // _HAS_CXX20

// TUPLE INTERFACE TO array
template <size_t _Idx, class _Ty, size_t _Size>
_NODISCARD constexpr _Ty& get(array<_Ty, _Size>& _Arr) noexcept {
    static_assert(_Idx < _Size, "array index out of bounds");
    return _Arr._Elems[_Idx];
}

template <size_t _Idx, class _Ty, size_t _Size>
_NODISCARD constexpr const _Ty& get(const array<_Ty, _Size>& _Arr) noexcept {
    static_assert(_Idx < _Size, "array index out of bounds");
    return _Arr._Elems[_Idx];
}

template <size_t _Idx, class _Ty, size_t _Size>
_NODISCARD constexpr _Ty&& get(array<_Ty, _Size>&& _Arr) noexcept {
    static_assert(_Idx < _Size, "array index out of bounds");
    return _STD move(_Arr._Elems[_Idx]);
}

template <size_t _Idx, class _Ty, size_t _Size>
_NODISCARD constexpr const _Ty&& get(const array<_Ty, _Size>&& _Arr) noexcept {
    static_assert(_Idx < _Size, "array index out of bounds");
    return _STD move(_Arr._Elems[_Idx]);
}

#if _HAS_TR1_NAMESPACE
namespace _DEPRECATE_TR1_NAMESPACE tr1 {
    using _STD array;
    using _STD get;
} // namespace tr1
#endif // _HAS_TR1_NAMESPACE
_STD_END

#pragma pop_macro("new")
_STL_RESTORE_CLANG_WARNINGS
#pragma warning(pop)
#pragma pack(pop)
#endif // _STL_COMPILER_PREPROCESSOR
#endif // _ARRAY_