endian.h File Reference

Endianness detection and byte swapping utilities. More...

#include <cstdint>
#include <cstring>
#include <type_traits>

Include dependency graph for endian.h:

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Enumerations
enum class	qb::endian::order { little , big , unknown }
	Enumeration of byte order types. More...

Functions
constexpr order	qb::endian::native_order ()
	Determines the system's native byte order at runtime.
constexpr bool	qb::endian::is_little_endian ()
	Checks if the system is little-endian at compile time when possible.
constexpr bool	qb::endian::is_big_endian ()
	Checks if the system is big-endian.
template<typename T>
T	qb::endian::byteswap (T value)
	Swaps the byte order of a value.
template<typename T>
T	qb::endian::to_big_endian (T value)
	Converts a value from native endianness to big-endian.
template<typename T>
T	qb::endian::from_big_endian (T value)
	Converts a value from big-endian to native endianness.
template<typename T>
T	qb::endian::to_little_endian (T value)
	Converts a value from native endianness to little-endian.
template<typename T>
T	qb::endian::from_little_endian (T value)
	Converts a value from little-endian to native endianness.

Detailed Description

Endianness detection and byte swapping utilities.

This file provides utilities for detecting the system's native endianness and converting values between different byte orders (little endian and big endian). It includes functions for runtime and compile-time endianness detection, as well as safe byte-swapping operations that work with arithmetic and enum types.

Author

qb - C++ Actor Framework

Copyright

Copyright (c) 2011-2025 qb - isndev (cpp.actor) 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.

Enumeration Type Documentation

order

enum class qb::endian::order

strong

Enumeration of byte order types.

Enumerator
little	Little-endian (least significant byte first)
big	Big-endian (most significant byte first)
unknown	Unknown endianness.

Function Documentation

native_order()

order qb::endian::native_order ( )

constexpr

Determines the system's native byte order at runtime.

Uses compiler macros for detection when available, with a fallback to runtime detection using a union.

Returns

The native byte order of the system

is_little_endian()

bool qb::endian::is_little_endian ( )

constexpr

Checks if the system is little-endian at compile time when possible.

Uses compiler macros for detection when available, with a fallback to runtime detection.

Returns

true if system is little-endian, false otherwise

is_big_endian()

bool qb::endian::is_big_endian ( )

constexpr

Checks if the system is big-endian.

Returns

true if system is big-endian, false otherwise

byteswap()

template<typename T>

T qb::endian::byteswap ( T value )

inline

Swaps the byte order of a value.

Reverses the bytes of any trivially copyable type. This function is safe to use with any arithmetic or enum type.

Template Parameters

T	The type of value to byte-swap (must be arithmetic or enum and trivially copyable)

Parameters

value

The value to byte-swap

Returns

The byte-swapped value

to_big_endian()

template<typename T>

T qb::endian::to_big_endian ( T value )

inline

Converts a value from native endianness to big-endian.

Template Parameters

T	The type of value to convert

Parameters

value

The value to convert

Returns

The value in big-endian byte order

from_big_endian()

template<typename T>

T qb::endian::from_big_endian ( T value )

inline

Converts a value from big-endian to native endianness.

Template Parameters

T	The type of value to convert

Parameters

value

The big-endian value to convert

Returns

The value in native byte order

to_little_endian()

template<typename T>

T qb::endian::to_little_endian ( T value )

inline

Converts a value from native endianness to little-endian.

Template Parameters

T	The type of value to convert

Parameters

value

The value to convert

Returns

The value in little-endian byte order

from_little_endian()

template<typename T>

T qb::endian::from_little_endian ( T value )

inline

Converts a value from little-endian to native endianness.

Template Parameters

T	The type of value to convert

Parameters

value

The little-endian value to convert

Returns

The value in native byte order