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std::byte

From cppreference.com
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Defined in header <cstddef>
enum class byte : unsigned char {} ;
(since C++17)

std::byte is a distinct type that implements the concept of byte as specified in the C++ language definition.

Like char and unsigned char, it can be used to access raw memory occupied by other objects (object representation), but unlike those types, it is not a character type and is not an arithmetic type. A byte is only a collection of bits, and only bitwise logic operators are defined for it.

Contents

[edit] Non-member functions

std::to_integer

template <class IntegerType>
 constexpr IntegerType to_integer(std::byte b) noexcept;
(since C++17)

Equivalent to: return IntegerType(b); This overload only participates in overload resolution if std::is_integral_v<IntegerType> is true.

std::operator<<=,operator>>=

template <class IntegerType>
 constexpr std::byte& operator<<=(std::byte& b, IntegerType shift) noexcept;
(1) (since C++17)
template <class IntegerType>
 constexpr std::byte& operator>>=(std::byte& b, IntegerType shift) noexcept;
(2) (since C++17)
1) Equivalent to: return b = std::byte(static_cast<unsigned char>(b) << shift); This overload only participates in overload resolution if std::is_integral_v<IntegerType> is true.
2) Equivalent to: return b = std::byte(static_cast<unsigned char>(b) >> shift);

This overload only participates in overload resolution if std::is_integral_v<IntegerType> is true.

std::operator<<,operator>>

template <class IntegerType>
 constexpr std::byte operator <<(std::byte b, IntegerType shift) noexcept;
(1) (since C++17)
template <class IntegerType>
 constexpr std::byte operator >>(std::byte b, IntegerType shift) noexcept;
(2) (since C++17)
1) Equivalent to: return std::byte(static_cast<unsigned char>(b) << shift); This overload only participates in overload resolution if std::is_integral_v<IntegerType> is true.
2) Equivalent to: return std::byte(static_cast<unsigned char>(b) >> shift);

This overload only participates in overload resolution if std::is_integral_v<IntegerType> is true.

std::operator|=,operator&=,operator^=

constexpr std::byte& operator|=(std::byte& l, std::byte r) noexcept;
(1) (since C++17)
constexpr std::byte& operator&=(std::byte& l, std::byte r) noexcept;
(2) (since C++17)
constexpr std::byte& operator^=(std::byte& l, std::byte r) noexcept;
(3) (since C++17)
1) Equivalent to: return l = std::byte(static_cast<unsigned char>(l) | static_cast<unsigned char>(r));.
2) Equivalent to: return l = std::byte(static_cast<unsigned char>(l) & static_cast<unsigned char>(r));.
3) Equivalent to: return l = std::byte(static_cast<unsigned char>(l) ^ static_cast<unsigned char>(r));.

std::operator|,operator&,operator^,operator~

constexpr std::byte operator|(std::byte l, std::byte r) noexcept;
(1) (since C++17)
constexpr std::byte operator&(std::byte l, std::byte r) noexcept;
(2) (since C++17)
constexpr std::byte operator^(std::byte l, std::byte r) noexcept;
(3) (since C++17)
constexpr std::byte operator~(std::byte b) noexcept;
(4) (since C++17)
1) Equivalent to: return std::byte(static_cast<unsigned char>(l) | static_cast<unsigned char>(r));.
2) Equivalent to: return std::byte(static_cast<unsigned char>(l) & static_cast<unsigned char>(r));.
3) Equivalent to: return std::byte(static_cast<unsigned char>(l) ^ static_cast<unsigned char>(r));.
4) Equivalent to: return std::byte(~static_cast<unsigned char>(b));

[edit] Notes

A numeric value n can be converted to a byte value using std::byte{n} , due to C++17 relaxed enum class initialization rules.

A byte can be converted to a numeric value (such as to produce a integer hash of an object) using std::to_integer

[edit] Example