#pragma once

using uint8_t   = unsigned char;
using uint16_t  = unsigned short;
using uint32_t  = unsigned int;
using uint64_t  = unsigned long long;

using int8_t    = signed char;
using int16_t   = signed short;
using int32_t   = signed int;
using int64_t   = signed long long;

using size_t    = uint64_t;
using uintptr_t = uint64_t;

static_assert(sizeof(size_t) == sizeof(void*), "size_t should be pointer size");
static_assert(sizeof(uintptr_t) == sizeof(void*), "size_t should be pointer size");

namespace std
{

template<typename T> concept integral = __is_integral(T);
template<typename T> concept signed_integral = integral<T> && __is_signed(T);
template<typename T> concept unsigned_integral = integral<T> && __is_unsigned(T);

template<typename T> constexpr bool is_trivially_destructible_v = __is_trivially_destructible(T);
template<typename T, typename... Args> constexpr bool is_constructible_v = __is_constructible(T, Args...);
template<typename T> constexpr bool is_default_constructible_v = __is_constructible(T);
template<typename T> constexpr bool is_copy_constructible_v = __is_constructible(T, const T&);
template<typename T> constexpr bool is_move_constructible_v = __is_constructible(T, T&&);
template<typename T> constexpr bool is_copy_assignable_v = __is_assignable(T, const T&);
template<typename T> constexpr bool is_move_assignable_v = __is_assignable(T, T&&);
template<typename T> constexpr bool is_trivially_copyable_v = __is_trivially_copyable(T);

template<typename U, typename V> constexpr bool _is_same_helper = false;
template<typename T> constexpr bool _is_same_helper<T, T> = true;
template<typename U, typename V> concept same_as = _is_same_helper<U, V> && _is_same_helper<V, U>;

template<typename T> struct make_void { using type = void; };
template<typename T> using void_t = make_void<T>::type;

template<typename T, typename = void> struct _add_reference_helper { using lvalue = T; using rvalue = T; };
template<typename T> struct _add_reference_helper<T, void_t<T&>> { using lvalue = T&; using rvalue = T&&; };
template<typename T> using add_lvalue_reference_t = _add_reference_helper<T>::lvalue;
template<typename T> using add_rvalue_reference_t = _add_reference_helper<T>::rvalue;

template<typename T> struct remove_reference { using type = T; };
template<typename T> struct remove_reference<T&> { using type = T; };
template<typename T> struct remove_reference<T&&> { using type = T; };
template<typename T> using remove_reference_t = remove_reference<T>::type;

template<typename T>
consteval add_rvalue_reference_t<T> declval()
{
    static_assert(false, "Don't use declval outside of constant evaluation");
}

template<typename From, typename To>
concept convertible_to = __is_convertible(From, To) && requires { static_cast<To>(declval<From>()); };

template<typename T>
constexpr remove_reference_t<T>&& move(T&& r) noexcept
{
    return static_cast<remove_reference_t<T>&&>(r);
}

template<typename T>
constexpr T&& forward(remove_reference_t<T>& r) noexcept
{
    return static_cast<T&&>(r);
}

template<typename T>
constexpr T&& forward(remove_reference_t<T>&& r) noexcept // NOLINT
{
    return static_cast<T&&>(r);
}

template<typename T, typename U>
constexpr T exchange(T& obj, U&& new_value)
{
    T old_value = std::move(obj);
    obj = std::forward<U>(new_value);
    return old_value;
}

enum __attribute__((__may_alias__)) byte : uint8_t {};
static_assert(sizeof(byte) == 1, "");

template<typename To, typename From>
requires (sizeof(To) == sizeof(From)) && is_trivially_copyable_v<To> && is_trivially_copyable_v<From>
constexpr To bit_cast(const From& from) noexcept
{
    return __builtin_bit_cast(To, from);
}

template<typename T>
class initializer_list
{
    const T*    m_begin = nullptr;
    size_t      m_size  = 0;

public:
    constexpr initializer_list() noexcept = default;

    constexpr size_t size() const noexcept { return m_size; }
    constexpr const T* begin() const noexcept { return m_begin; }
    constexpr const T* end() const noexcept { return m_begin + m_size; }
};

} // namespace std

static_assert(std::same_as<int, int>, "");
static_assert(!std::same_as<int, void>, "");

static_assert(std::same_as<std::remove_reference_t<int>, int>, "");
static_assert(std::same_as<std::remove_reference_t<int&>, int>, "");
static_assert(std::same_as<std::remove_reference_t<int&&>, int>, "");

static_assert(std::same_as<std::add_lvalue_reference_t<int>, int&>, "");
static_assert(std::same_as<std::add_lvalue_reference_t<int&>, int&>, "");
static_assert(std::same_as<std::add_lvalue_reference_t<int&&>, int&>, "");
static_assert(std::same_as<std::add_lvalue_reference_t<void>, void>, "");

static_assert(std::same_as<std::add_rvalue_reference_t<int>, int&&>, "");
static_assert(std::same_as<std::add_rvalue_reference_t<int&>, int&>, "");
static_assert(std::same_as<std::add_rvalue_reference_t<int&&>, int&&>, "");
static_assert(std::same_as<std::add_rvalue_reference_t<void>, void>, "");

static_assert(std::convertible_to<int*, const int*>, "");
static_assert(!std::convertible_to<int*, float*>, "");

constexpr void* operator new(size_t, void* ptr)
{
    return ptr;
}