bitmasked

Bitmasked is an adjective used in computing to describe data or values that have been processed by a bitmask. A bitmask is a binary pattern used with bitwise operations to select, modify, or ignore specific bits within a value. When something is bitmasked, its meaningful information is typically contained within a subset of bits, while the other bits are cleared or treated as irrelevant.

Common bitmask operations include AND to clear or retain bits, OR to set bits, XOR to toggle bits, and NOT to invert bits. Shifts can align bits with a mask. For example, to test whether a given bit is set, use (value & (1 << i)) != 0. To set, OR with the mask; to clear, AND with the complement; to toggle, XOR with the mask. These patterns enable precise control over individual bits within an integer.

Bitmasked data are widely used to implement flag fields, permissions, feature toggles, and compact representations of state in protocol headers or file formats. They allow efficient storage by packing multiple boolean or small-range values into a single integer. In algorithm design, bitmasks are commonly used to enumerate subsets, mask out irrelevant elements, or represent dynamic programming states.

Notes on usage: bitmasked values rely on fixed-width integers. In many languages, unsigned types yield more predictable results for bit operations, while signed types can introduce sign-extension in shifts. Endianness generally does not affect bitwise masks, but portable code should rely on explicit masks and width-safe types. The term bitmasked is less common than bitmask itself, and in formal documentation the noun bitmask is preferred; bitmasked is typically used as an adjectival descriptor of data or operations.