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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#pragma once
#include <cstring>
namespace fsa {
template <typename T>
class Unaligned {
private:
char _data[sizeof(T)];
public:
Unaligned() = delete;
Unaligned(const Unaligned &) = delete;
Unaligned(Unaligned &&) = delete;
Unaligned &operator=(const Unaligned &) = default;
Unaligned &operator=(Unaligned &&) = default;
static_assert(std::is_trivial_v<T>);
static_assert(alignof(T) > 1, "value is always aligned");
constexpr static Unaligned &at(void *p) noexcept {
return *reinterpret_cast<Unaligned*>(p);
}
constexpr static const Unaligned &at(const void *p) noexcept {
return *reinterpret_cast<const Unaligned*>(p);
}
constexpr static Unaligned *ptr(void *p) noexcept {
return reinterpret_cast<Unaligned*>(p);
}
constexpr static const Unaligned *ptr(const void *p) noexcept {
return reinterpret_cast<const Unaligned*>(p);
}
T read() const noexcept {
T value;
static_assert(sizeof(_data) == sizeof(value));
memcpy(&value, _data, sizeof(value));
return value;
}
void write(const T &value) noexcept {
static_assert(sizeof(_data) == sizeof(value));
memcpy(_data, &value, sizeof(value));
}
operator T () const noexcept { return read(); }
Unaligned &operator=(const T &value) noexcept {
write(value);
return *this;
}
};
}
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