A bit operation applies an operator to the corresponding bits of integer operands. Treating each bit as a truth value makes & resemble logical AND, | resemble logical OR, and ^ represent exclusive OR; ~ complements every bit. Unlike && and ||, bitwise operators do not short-circuit. section 5.7.2
Representing a set with bits
Each corvid receives a distinct power-of-two constant, so one bit identifies each member. |= adds a member, while & tests membership.\n\n #define FLOCK_MAGPIE 1U\n #define FLOCK_RAVEN 2U\n #define FLOCK_JAY 4U\n #define FLOCK_CHOUGH 8U\n #define FLOCK_EMPTY 0U\n\n unsigned flock = FLOCK_EMPTY;\n\n if (something) flock |= FLOCK_JAY;\n\n if (flock & FLOCK_CHOUGH)\n do_something_chough_specific(flock);\n\nThe same operations correspond to set union, intersection, symmetric difference, and complement when bits represent set membership. section 5.7.2
C23 adds named bit operations in <stdbit.h> for unsigned integers, including counting one-bits, detecting a single set bit, finding bit width, and finding the highest-numbered singleton bit. These functions define results for every argument value, including exceptional cases, although a platform might not yet provide the header. section 5.7.2 section 8.2
