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std::byte(3) C++ Standard Libary std::byte(3) NAME std::byte - std::byte Synopsis 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 oc- cupied 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 the only operators defined for it are the bitwise ones. Non-member functions std::to_integer template <class IntegerType> (since C++17) constexpr IntegerType to_integer( std::byte b ) noexcept; Equivalent to: return IntegerType(b); This overload participates in overload resolution only if std::is_integral_v<IntegerType> is true. std::operator<<=,operator>>= template <class IntegerType> constexpr std::byte& operator<<=( std::byte& b, IntegerType shift (1) (since C++17) ) noexcept; template <class IntegerType> constexpr std::byte& operator>>=( std::byte& b, IntegerType shift (2) (since C++17) ) noexcept; 1) Equivalent to: return b = b << shift; This overload participates in overload resolution only if std::is_integral_v<IntegerType> is true. 2) Equivalent to: return b = b >> shift; This overload participates in overload resolution only if std::is_integral_v<IntegerType> is true. std::operator<<,operator>> template <class IntegerType> constexpr std::byte operator <<( std::byte b, IntegerType shift ) (1) (since C++17) noexcept; template <class IntegerType> constexpr std::byte operator >>( std::byte b, IntegerType shift ) (2) (since C++17) noexcept; 1) Equivalent to: return std::byte(static_cast<unsigned int>(b) << shift); This overload participates in overload resolution only if std::is_inte- gral_v<IntegerType> is true. 2) Equivalent to: return std::byte(static_cast<unsigned int>(b) >> shift); This overload participates in overload resolution only if std::is_integral_v<IntegerType> is true. std::operator|=,operator&=,operator^= constexpr std::byte& operator|=( std::byte& l, std::byte r ) (1) (since C++17) noexcept; constexpr std::byte& operator&=( std::byte& l, std::byte r ) (2) (since C++17) noexcept; constexpr std::byte& operator^=( std::byte& l, std::byte r ) (3) (since C++17) noexcept; 1) Equivalent to: return l = l | r;. 2) Equivalent to: return l = l & r;. 3) Equivalent to: return l = l ^ r;. std::operator|,operator&,operator^,operator~ constexpr std::byte operator|( std::byte l, std::byte r ) (1) (since C++17) noexcept; constexpr std::byte operator&( std::byte l, std::byte r ) (2) (since C++17) noexcept; constexpr std::byte operator^( std::byte l, std::byte r ) (3) (since C++17) noexcept; constexpr std::byte operator~( std::byte b ) noexcept; (4) (since C++17) 1) Equivalent to: return std::byte(static_cast<unsigned int>(l) | static_cast<unsigned int>(r));. 2) Equivalent to: return std::byte(static_cast<unsigned int>(l) & static_cast<unsigned int>(r));. 3) Equivalent to: return std::byte(static_cast<unsigned int>(l) ^ static_cast<unsigned int>(r));. 4) Equivalent to: return std::byte(~static_cast<unsigned int>(b)); 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 an integer hash of an object) using std::to_integer. Feature-test macro: __cpp_lib_byte Example // Run this code #include <iostream> #include <cstddef> #include <bitset> std::ostream& operator<< (std::ostream& os, std::byte b) { return os << std::bitset<8>(std::to_integer<int>(b)); } int main() { std::byte b{42}; std::cout << "1. " << b << '\n'; // b *= 2 compilation error b <<= 1; std::cout << "2. " << b << '\n'; b >>= 1; std::cout << "3. " << b << '\n'; std::cout << "4. " << (b << 1) << '\n'; std::cout << "5. " << (b >> 1) << '\n'; b |= std::byte{0b11110000}; std::cout << "6. " << b << '\n'; b &= std::byte{0b11110000}; std::cout << "7. " << b << '\n'; b ^= std::byte{0b11111111}; std::cout << "8. " << b << '\n'; } Output: 1. 00101010 2. 01010100 3. 00101010 4. 01010100 5. 00010101 6. 11111010 7. 11110000 8. 00001111 http://cppreference.com 2022.07.31 std::byte(3)
NAME | Synopsis | Non-member functions | Notes | Example | Output:
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