set_unaligned.h File Reference

Write little-endian values through possibly unaligned pointers. More...

#include "CxxUtils/restrict.h"
#include <cstring>
#include <bit>
#include <cstdint>

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Namespaces
	CxxUtils

Functions
uint16_t	CxxUtils::htole16 (uint16_t x)
uint32_t	CxxUtils::htole32 (uint32_t x)
uint64_t	CxxUtils::htole64 (uint64_t x)
void	CxxUtils::set_unaligned16 (uint8_t *ATH_RESTRICT &p, uint16_t val)
	Write a 2-byte little-endian value to a possibly unaligned pointer. More...
void	CxxUtils::set_unaligned32 (uint8_t *ATH_RESTRICT &p, uint32_t val)
	Write a 4-byte little-endian value to a possibly unaligned pointer. More...
void	CxxUtils::set_unaligned64 (uint8_t *ATH_RESTRICT &p, uint64_t val)
	Write an 8-byte little-endian value to a possibly unaligned pointer. More...
void	CxxUtils::set_unaligned_float (uint8_t *ATH_RESTRICT &p, float val)
	Write a little-endian float value to a possibly unaligned pointer. More...
void	CxxUtils::set_unaligned_double (uint8_t *ATH_RESTRICT &p, double val)
	Write a little-endian double value to a possibly unaligned pointer. More...
template<class T >
void	CxxUtils::set_unaligned (uint8_t *ATH_RESTRICT &p, T val)
	Define templated versions of the above functions. More...
template<>
void	CxxUtils::set_unaligned< uint8_t > (uint8_t *ATH_RESTRICT &p, uint8_t val)
template<>
void	CxxUtils::set_unaligned< uint16_t > (uint8_t *ATH_RESTRICT &p, uint16_t val)
template<>
void	CxxUtils::set_unaligned< uint32_t > (uint8_t *ATH_RESTRICT &p, uint32_t val)
template<>
void	CxxUtils::set_unaligned< uint64_t > (uint8_t *ATH_RESTRICT &p, uint64_t val)
template<>
void	CxxUtils::set_unaligned< float > (uint8_t *ATH_RESTRICT &p, float f)
template<>
void	CxxUtils::set_unaligned< double > (uint8_t *ATH_RESTRICT &p, double f)
template<>
void	CxxUtils::set_unaligned< int8_t > (uint8_t *ATH_RESTRICT &p, int8_t val)
template<>
void	CxxUtils::set_unaligned< int16_t > (uint8_t *ATH_RESTRICT &p, int16_t val)
template<>
void	CxxUtils::set_unaligned< int32_t > (uint8_t *ATH_RESTRICT &p, int32_t val)
template<>
void	CxxUtils::set_unaligned< int64_t > (uint8_t *ATH_RESTRICT &p, int64_t val)

Detailed Description

Write little-endian values through possibly unaligned pointers.

Author

scott snyder snyde.nosp@m.r@bn.nosp@m.l.gov

Date

Jan, 2015 Doing, eg,

char* p = ...;
int* ip = reinterpret_cast<int*>(p);
*ip++ = i;

is undefined if p isn't aligned to an int boundary. It further will read the value using the host endianness, which is an issue for the common use case of reading persistent data.

The functions here allow writing little-endian data via possibly unaligned pointers regardless of the host byte ordering and without relying on undefined behavior.

Definition in file set_unaligned.h.