genode/repos/base-hw/src/include/base/internal/align_at.h

55 lines
1.2 KiB
C++

/*
* \brief Utility for aligned object members
* \author Stefan Kalkowski
* \date 2017-09-01
*/
/*
* Copyright (C) 2017 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
#ifndef _INCLUDE__BASE__INTERNAL__ALIGN_AT_H_
#define _INCLUDE__BASE__INTERNAL__ALIGN_AT_H_
#include <util/construct_at.h>
#include <base/stdint.h>
namespace Genode {
template<typename, size_t> class Align_at;
}
template <typename T, Genode::size_t ALIGN>
class Genode::Align_at
{
private:
char _space[sizeof(T) + ALIGN - 1];
T & _obj;
void * _start_addr()
{
bool aligned = !((addr_t)_space & (ALIGN - 1));
return aligned ? (void*)_space
: (void*)(((addr_t)_space & ~(ALIGN - 1)) + ALIGN);
}
public:
template <typename... ARGS>
Align_at(ARGS &&... args)
: _obj(*construct_at<T>(_start_addr(), args...)) { }
~Align_at() { _obj.~T(); }
T * operator -> () { return &_obj; }
T const * operator -> () const { return &_obj; }
T & operator * () { return _obj; }
T const & operator * () const { return _obj; }
};
#endif /* _INCLUDE__BASE__INTERNAL__ALIGN_AT_H_ */