Bit

Utility functions for manipulating binary numbers.

A reverse engineered version of C++20's and C++23's <bit> header.

ETL_CONSTEXPR14 = constexpr for C++14 or above

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bit_cast

template <typename TDestination, typename TSource>>

ETL_CONSTEXPR14 TDestination bit_cast(const TSource& source) ETL_NOEXCEPT

Returns a value of type TDestination by reinterpreting the TSource object.

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byteswap

template <typename T>

ETL_CONSTEXPR14 T byteswap(T n) ETL_NOEXCEPT

Reverses the bytes in n.

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has_single_bit

template <typename T>

ETL_CONSTEXPR14 bool has_single_bit(T n) ETL_NOEXCEPT

Checks if n is a power of two, or has one bit set.

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bit_ceil

template <typename T>

ETL_CONSTEXPR14 T bit_ceil(T n);

Calculates the smallest power of two, that is not smaller than n.

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bit_floor

template <typename T>

ETL_CONSTEXPR14 T bit_floor(T n) ETL_NOEXCEPT

Calculates the smallest power of two, that is not greater than n.

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bit_width

template <typename T>

ETL_CONSTEXPR14 T bit_width(T n) ETL_NOEXCEPT

If n is not 0, calculates the number of bits needed to store it.

If n is 0, then the result is 0.

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rotl

template <typename T>

ETL_NODISCARD ETL_CONSTEXPR14 T rotl(T value, int n) ETL_NOEXCEPT

Computes a left circular shift of value by n.

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rotr

template <typename T>

ETL_NODISCARD ETL_CONSTEXPR14 T rotr(T value, int n) ETL_NOEXCEPT

Computes a right circular shift of value by n.

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countl_zero

template <typename T>

ETL_NODISCARD ETL_CONSTEXPR14 int countl_zero(T value) ETL_NOEXCEPT

Returns the number of consecutive 0 bits in n, starting from the most significant bit (left).

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countl_one

template <typename T>

ETL_NODISCARD ETL_CONSTEXPR14 int countl_one(T value) ETL_NOEXCEPT

Returns the number of consecutive 1 bits in n, starting from the most significant bit (left).

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countr_zero

template <typename T>

ETL_NODISCARD ETL_CONSTEXPR14 int countr_zero(T value) ETL_NOEXCEPT

Returns the number of consecutive 0 bits in n, starting from the least significant bit (right).

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countr_one

template <typename T>

ETL_NODISCARD ETL_CONSTEXPR14 int countr_one(T value) ETL_NOEXCEPT

Returns the number of consecutive 1 bits in n, starting from the least significant bit (right).

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popcount

template <typename T>

ETL_NODISCARD ETL_CONSTEXPR14 int popcount(T value) ETL_NOEXCEPT

Counts the number of 1 bits in an unsigned integer.

bit.h