なんちゃって2進リテラル

bits.c

#define CONCAT2(x,y) x ## y
#define CONCAT(x,y) CONCAT2(x,y)
#define VAL_END 0)
#define VAL0_END 0) >> 1
#define VAL1_END 0) >> 2
#define VAL2_END 0) >> 3
#define VAL3_END 0) >> 4
#define VAL4_END 0) >> 5
#define VAL5_END 0) >> 6
#define VAL6_END 0) >> 7
#define VAL0(b) (b << 0) + VAL
#define VAL1(b) (b << 1) + VAL0
#define VAL2(b) (b << 2) + VAL1
#define VAL3(b) (b << 3) + VAL2
#define VAL4(b) (b << 4) + VAL3
#define VAL5(b) (b << 5) + VAL4
#define VAL6(b) (b << 6) + VAL5
#define VAL7(b) (b << 7) + VAL6
#define VAL(x) ((CONCAT(VAL7 x,_END))
#define X (1)
#define _ (0)

#if !defined(__cplusplus)
#define static_assert _Static_assert
#endif

static_assert(VAL(X) == 1, "");
static_assert(VAL(_) == 0, "");
static_assert(VAL(_ _) == 0, "");
static_assert(VAL(_ X) == 1, "");
static_assert(VAL(X _) == 2, "");
static_assert(VAL(X X) == 3, "");
static_assert(VAL(_ X _ X) == 5, "");
static_assert(VAL(X _ _ _) == 0x08, "");
static_assert(VAL(X X X X) == 0x0f, "");
static_assert(VAL(_ X _ X X _ X _) == 0x5a, "");
static_assert(VAL(X _ X _ X _ X _) == 0xaa, "");
static_assert(VAL(X X _ X X _ X X) == 0xdb, "");
static_assert(VAL(X X X X X X X X) == 0xff, "");

static_assert(VAL(_ _ _ _ _) == 0x00, "");
static_assert(VAL(X X X X X) == 0x1f, "");
static_assert(VAL(_ X _ X _) == 0x0a, "");
static_assert(VAL(_ X _ X _) == 0x0a, "");
static_assert(VAL(X _ _ X X) == 0x13, "");

static const unsigned char pi[] = {
    VAL(_ _ _ _ _),
    VAL(X X X X X),
    VAL(_ X _ X _),
    VAL(_ X _ X _),
    VAL(X _ _ X X),
    VAL(_ _ _ _ _),
};