bits.h File Reference

POD-compatible fixed-size bitflag storage (jh::pod::bitflags<N>). More...

#include <cstdint>
#include <type_traits>
#include "jh/pods/array.h"
#include "jh/macros/platform.h"
#include <bit>

Go to the source code of this file.

Classes
struct	jh::pod::bitflags< N >
	POD-compatible fixed-size bitflags structure.Generic fallback specialization for non-native sizes (e.g. 24, 120 bits, etc). More...
struct	jh::pod::bitflags< 8 >
	Specialization for 8-bit bitflags. More...
struct	jh::pod::bitflags< 16 >
	Specialization for 16-bit bitflags. More...
struct	jh::pod::bitflags< 32 >
	Specialization for 32-bit bitflags. More...
struct	jh::pod::bitflags< 64 >
	Specialization for 64-bit bitflags. More...

Namespaces
namespace	jh::pod
	Aggregated entry point for Plain-Old-Data and layout-stable value utilities.

Concepts
concept	jh::pod::std_uint
	Internal constraint for native unsigned integer types.

Functions
template<std_uint UInt>
constexpr auto	jh::pod::uint_to_bytes (const UInt val)
	Convert an unsigned integer into a little-endian byte array.
template<std::uint16_t N>
constexpr auto	jh::pod::bytes_to_uint (const array< std::uint8_t, N > &arr)
	Convert a little-endian byte array into an unsigned integer.
template<std::uint16_t N>
constexpr bitflags< N >	jh::pod::operator| (const bitflags< N > &lhs, const bitflags< N > &rhs) noexcept
template<std::uint16_t N>
constexpr bitflags< N >	jh::pod::operator& (const bitflags< N > &lhs, const bitflags< N > &rhs) noexcept
template<std::uint16_t N>
constexpr bitflags< N >	jh::pod::operator^ (const bitflags< N > &lhs, const bitflags< N > &rhs) noexcept
template<std::uint16_t N>
constexpr bitflags< N >	jh::pod::operator~ (const bitflags< N > &v) noexcept
template<std::uint16_t N>
constexpr array< std::uint8_t, N/8 >	jh::pod::to_bytes (bitflags< N > f)
	Serialize a bitflags<N> into a little-endian byte array (snapshot).
template<std::uint16_t N>
constexpr bitflags< N >	jh::pod::from_bytes (array< std::uint8_t, N/8 > arr)
	Deserialize a bitflags<N> from a byte array (snapshot).

Variables
constexpr std::uint16_t	jh::pod::max_pod_bitflags_bytes = 4 * 1024
	Maximum allowed size of a POD bitflags structure: 4KB (4096 bytes).
template<std::uint16_t N>
constexpr bool	jh::pod::is_native_bitflags = N == 8 || N == 16 || N == 32 || N == 64

Detailed Description

POD-compatible fixed-size bitflag storage (jh::pod::bitflags<N>).

Copyright

Copyright 2025 JeongHan-Bae <mastropseudo@gmail.com>
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Full license: GitHub

Design Goals

• POD-only: trivially copyable, standard layout, no constructors or destructors
• Compact: exactly N/8 bytes of storage (or one native integer)
• Deterministic ABI: safe for memcpy, file mapping, and raw buffers
• Constexpr-friendly: most operations available at compile-time
• No runtime overhead: zero dynamic allocation, no virtual dispatch

Note

Unlike std::bitset, this type:

• Has a fixed ABI and is always POD
• Provides minimal, direct bitwise operations
• Is explicitly designed for low-level containers and serialization