mirror of
https://github.com/mutouyun/cpp-ipc.git
synced 2025-12-07 01:06:45 +08:00
75 lines
2.0 KiB
C++
75 lines
2.0 KiB
C++
/**
|
|
* \file libipc/aligned.h
|
|
* \author mutouyun (orz@orzz.org)
|
|
* \brief Defines the type suitable for use as uninitialized storage for types of given type.
|
|
*/
|
|
#pragma once
|
|
|
|
#include <array>
|
|
#include <cstddef>
|
|
|
|
#include "libipc/imp/byte.h"
|
|
|
|
namespace ipc {
|
|
|
|
/**
|
|
* \brief The type suitable for use as uninitialized storage for types of given type.
|
|
* std::aligned_storage is deprecated in C++23, so we define our own.
|
|
* \tparam T The type to be aligned.
|
|
* \tparam AlignT The alignment of the type.
|
|
* \see https://en.cppreference.com/w/cpp/types/aligned_storage
|
|
* https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1413r3.pdf
|
|
*/
|
|
template <typename T, std::size_t AlignT = alignof(T)>
|
|
class aligned {
|
|
alignas(AlignT) std::array<ipc::byte, sizeof(T)> storage_;
|
|
|
|
public:
|
|
/**
|
|
* \brief Returns a pointer to the aligned storage.
|
|
* \return A pointer to the aligned storage.
|
|
*/
|
|
T *ptr() noexcept {
|
|
return reinterpret_cast<T *>(storage_.data());
|
|
}
|
|
|
|
/**
|
|
* \brief Returns a pointer to the aligned storage.
|
|
* \return A pointer to the aligned storage.
|
|
*/
|
|
T const *ptr() const noexcept {
|
|
return reinterpret_cast<const T *>(storage_.data());
|
|
}
|
|
|
|
/**
|
|
* \brief Returns a reference to the aligned storage.
|
|
* \return A reference to the aligned storage.
|
|
*/
|
|
T &ref() noexcept {
|
|
return *ptr();
|
|
}
|
|
|
|
/**
|
|
* \brief Returns a reference to the aligned storage.
|
|
* \return A reference to the aligned storage.
|
|
*/
|
|
T const &ref() const noexcept {
|
|
return *ptr();
|
|
}
|
|
};
|
|
|
|
/**
|
|
* \brief Rounds up the given value to the given alignment.
|
|
* \tparam T The type of the value.
|
|
* \param value The value to be rounded up.
|
|
* \param alignment The alignment to be rounded up to.
|
|
* \return The rounded up value.
|
|
* \see https://stackoverflow.com/questions/3407012/c-rounding-up-to-the-nearest-multiple-of-a-number
|
|
*/
|
|
template <typename T>
|
|
constexpr T round_up(T value, T alignment) noexcept {
|
|
return (value + alignment - 1) & ~(alignment - 1);
|
|
}
|
|
|
|
} // namespace ipc
|