SizeToType.h

//
// Copyright 2013 - 2025 (C). Alex Robenko. All rights reserved.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
#pragma once
 
#include <array>
#include <cstdint>
 
namespace comms
{
 
namespace util
{
 
namespace details
{
 
template <std::size_t TSize>
struct SizeToTypeHelper {
    using Type = std::array<std::uint8_t, TSize>;
};
 
template <>
struct SizeToTypeHelper<1>
{
    using Type = std::uint8_t;
};
 
template <>
struct SizeToTypeHelper<2>
{
    using Type = std::uint16_t;
};
 
template <>
struct SizeToTypeHelper<4>
{
    using Type = std::uint32_t;
};
 
template <>
struct SizeToTypeHelper<8>
{
    using Type = std::uint64_t;
};
 
template <>
struct SizeToTypeHelper<3>
{
    using Type = SizeToTypeHelper<4>::Type;
};
 
template <>
struct SizeToTypeHelper<5>
{
    using Type = SizeToTypeHelper<8>::Type;
};
 
template <>
struct SizeToTypeHelper<6>
{
    using Type = SizeToTypeHelper<8>::Type;
};
 
template <>
struct SizeToTypeHelper<7>
{
    using Type = SizeToTypeHelper<8>::Type;
};
 
}  // namespace details
 
 
template <std::size_t TSize, bool TSigned = false>
class SizeToType
{
    using ByteType = typename SizeToType<1, TSigned>::Type;
 
public:
    using Type = std::array<ByteType, TSize>;
};
 
template <std::size_t TSize>
struct SizeToType<TSize, false>
{
    using Type = typename details::SizeToTypeHelper<TSize>::Type;
};
 
template <std::size_t TSize>
struct SizeToType<TSize, true>
{
    using Type = typename
        std::make_signed<
            typename SizeToType<TSize, false>::Type
        >::type;
};
 
template <std::size_t TSize, bool TSigned = false>
using SizeToTypeT = typename SizeToType<TSize, TSigned>::Type;
 
 
}  // namespace util
 
}  // namespace comms