ladybird/AK/Userspace.h
Emanuele Torre 5bf994d2d9 AK: Use C++20 concepts to only allow Userspace wrappers of pointers
It was a bit odd that you could create a Userspace<int> and that
Userspace<int>::ptr() returned an int instead of an int*.

Let's use C++20 concepts to only allow creating Userspace objects with
pointer types. :^)
2020-08-01 10:44:42 +02:00

72 lines
2.1 KiB
C++

/*
* Copyright (c) 2018-2020, 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/StdLibExtras.h>
#include <AK/Types.h>
namespace AK {
template<typename T>
concept PointerTypeName = IsPointer<T>::value;
template<PointerTypeName T>
class Userspace {
public:
Userspace() { }
operator bool() const { return m_ptr; }
operator FlatPtr() const { return (FlatPtr)m_ptr; }
#if defined(KERNEL)
Userspace(FlatPtr ptr)
: m_ptr(ptr)
{
}
FlatPtr ptr() const { return m_ptr; }
T unsafe_userspace_ptr() const { return (T)m_ptr; }
#else
Userspace(T ptr)
: m_ptr(ptr)
{
}
T ptr() const { return m_ptr; }
#endif
private:
#if defined(KERNEL)
FlatPtr m_ptr { 0 };
#else
T m_ptr { nullptr };
#endif
};
}
using AK::Userspace;