Utility Bitmask

group utility_bitmask

Functions

inline constexpr size_type word_index(size_type bit_index)

Returns the index of the word containing the specified bit.

Parameters:

bit_index – The index of the bit to query

Returns:

The index of the word containing the specified bit

inline constexpr size_type intra_word_index(size_type bit_index)

Returns the position within a word of the specified bit.

Parameters:

bit_index – The index of the bit to query

Returns:

The position within a word of the specified bit

inline void set_bit_unsafe(bitmask_type *bitmask, size_type bit_index)

Sets the specified bit to 1

This function is not thread-safe, i.e., attempting to update bits within the same word concurrently from multiple threads results in undefined behavior.

Parameters:

• bitmask – The bitmask containing the bit to set

• bit_index – Index of the bit to set

inline void clear_bit_unsafe(bitmask_type *bitmask, size_type bit_index)

Sets the specified bit to 0

This function is not thread-safe, i.e., attempting to update bits within the same word concurrently from multiple threads results in undefined behavior.

Parameters:

• bitmask – The bitmask containing the bit to clear

• bit_index – The index of the bit to clear

inline bool bit_is_set(bitmask_type const *bitmask, size_type bit_index)

Indicates whether the specified bit is set to 1

Parameters:

• bitmask – The bitmask containing the bit to clear

• bit_index – Index of the bit to test

Returns:

true The specified bit is 1

Returns:

false The specified bit is 0

inline bool bit_value_or(bitmask_type const *bitmask, size_type bit_index, bool default_value)

optional-like interface to check if a specified bit of a bitmask is set.

Parameters:

• bitmask – The bitmask containing the bit to clear

• bit_index – Index of the bit to test

• default_value – Value to return if bitmask is nullptr

Returns:

true The specified bit is 1

Returns:

false The specified bit is 0

Returns:

default_value if bitmask is nullptr

inline constexpr bitmask_type set_least_significant_bits(size_type n)

Returns a bitmask word with the n least significant bits set.

Behavior is undefined if n < 0 or if n >= size_in_bits<bitmask_type>()

Parameters:

n – The number of least significant bits to set

Returns:

A bitmask word with n least significant bits set

inline constexpr bitmask_type set_most_significant_bits(size_type n)

Returns a bitmask word with the n most significant bits set.

Behavior is undefined if n < 0 or if n >= size_in_bits<bitmask_type>()

Parameters:

n – The number of most significant bits to set

Returns:

A bitmask word with n most significant bits set