ladybird/AK/StdLibExtras.h
AnotherTest e4412f1f59 AK+Kernel: Make IntrusiveList capable of holding non-raw pointers
This should allow creating intrusive lists that have smart pointers,
while remaining free (compared to the impl before this commit) when
holding raw pointers :^)
As a sidenote, this also adds a `RawPtr<T>` type, which is just
equivalent to `T*`.
Note that this does not actually use such functionality, but is only
expected to pave the way for #6369, to replace NonnullRefPtrVector<T>
with intrusive lists.

As it is with zero-cost things, this makes the interface a bit less nice
by requiring the type name of what an `IntrusiveListNode` holds (and
optionally its container, if not RawPtr), and also requiring the type of
the container (normally `RawPtr`) on the `IntrusiveList` instance.
2021-04-16 22:26:52 +02:00

146 lines
3.5 KiB
C++

/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/StdLibExtraDetails.h>
#include <AK/Assertions.h>
constexpr unsigned round_up_to_power_of_two(unsigned value, unsigned power_of_two)
{
return ((value - 1) & ~(power_of_two - 1)) + power_of_two;
}
namespace std {
// NOTE: This is in the "std" namespace since some compiler features rely on it.
template<typename T>
constexpr T&& move(T& arg)
{
return static_cast<T&&>(arg);
}
}
using std::move;
namespace AK::Detail {
template<typename T>
struct _RawPtr {
using Type = T*;
};
}
namespace AK {
template<typename T>
auto declval() -> T;
template<class T>
constexpr T&& forward(RemoveReference<T>& param)
{
return static_cast<T&&>(param);
}
template<class T>
constexpr T&& forward(RemoveReference<T>&& param) noexcept
{
static_assert(!IsLvalueReference<T>, "Can't forward an rvalue as an lvalue.");
return static_cast<T&&>(param);
}
template<typename T, typename SizeType = decltype(sizeof(T)), SizeType N>
constexpr SizeType array_size(T (&)[N])
{
return N;
}
template<typename T>
constexpr T min(const T& a, const T& b)
{
return b < a ? b : a;
}
template<typename T>
constexpr T max(const T& a, const T& b)
{
return a < b ? b : a;
}
template<typename T>
constexpr T clamp(const T& value, const T& min, const T& max)
{
VERIFY(max >= min);
if (value > max)
return max;
if (value < min)
return min;
return value;
}
template<typename T, typename U>
constexpr T ceil_div(T a, U b)
{
static_assert(sizeof(T) == sizeof(U));
T result = a / b;
if ((a % b) != 0)
++result;
return result;
}
template<typename T, typename U>
inline void swap(T& a, U& b)
{
U tmp = move((U&)a);
a = (T &&) move(b);
b = move(tmp);
}
template<typename T, typename U = T>
constexpr T exchange(T& slot, U&& value)
{
T old_value = move(slot);
slot = forward<U>(value);
return old_value;
}
template<typename T>
using RawPtr = typename Detail::_RawPtr<T>::Type;
}
using AK::array_size;
using AK::ceil_div;
using AK::clamp;
using AK::declval;
using AK::exchange;
using AK::forward;
using AK::max;
using AK::min;
using AK::RawPtr;
using AK::swap;