苦肉の策だが。

#define CONCAT_(a, b) a ## b
#define CONCAT(a, b) CONCAT_(a, b)
#define STATIC_ASSERT(expr) typedef char CONCAT(STATIC_ASSERT_, __LINE__)[(expr) ? 1 : -1]

#define SQRT_A (2.236067977499790)
#define A (5)
#define B ((int)(SQRT_A * 100))

STATIC_ASSERT((A - SQRT_A * SQRT_A) < DBL_EPSILON * A);
STATIC_ASSERT((A - SQRT_A * SQRT_A) > -DBL_EPSILON * A);