#define UNUSED(x) (void)(x)
#define NELEMS(x) (sizeof(x) / sizeof((x)[0]))

#define PI 3.14159265358979323846
#define RAD(a)    ((a) * PI / 180)
#define DEG(a)    ((a) * 180 / PI)

// typedef char bit;

// Largely inspired by "Zed's Awesome Debug Macros"
// From http://c.learncodethehardway.org/book/ex20.html

#define BEGIN do {
#define END   } while (0)

#define EPRINT(...) fprintf(stderr, __VA_ARGS__)

#ifdef NDEBUG
#define DEBUG(M, ...)
#define DEBUG_LOC_FMT
#define DEBUG_LOC_VALS
#define DEBUG_LEVEL(X)
#else
#define DEBUG(M, ...)     EPRINT("[DEBUG] %s:%d %s: " M "\n", __FILE__, __LINE__, __func__, ##__VA_ARGS__)
#define DEBUG_LOC_FMT  "%s:%d %s: "
#define DEBUG_LOC_VALS , __FILE__, __LINE__, __func__
#define DEBUG_LEVEL(X)    X
#endif

#define STRERROR()        (errno == 0 ? "" : ": "), (errno == 0 ? "" : strerror(errno))

#define ERROR1(M, ...)    EPRINT(DEBUG_LEVEL("[ERROR] ") DEBUG_LOC_FMT M "\n" DEBUG_LOC_VALS, ##__VA_ARGS__)
#define WARN1(M, ...)     EPRINT(DEBUG_LEVEL("[WARN]  ") DEBUG_LOC_FMT M "\n" DEBUG_LOC_VALS, ##__VA_ARGS__)
#define CHECK1(A, M, ...) BEGIN if (!(A)) { ERROR1(M, ##__VA_ARGS__); goto error; } END

#define CERROR(M, ...)    EPRINT(DEBUG_LEVEL("[ERROR] ") DEBUG_LOC_FMT M "%s%s\n" DEBUG_LOC_VALS, ##__VA_ARGS__, STRERROR())

#define WARN(M, ...)      EPRINT(DEBUG_LEVEL("[WARN]  ") DEBUG_LOC_FMT M "%s%s\n" DEBUG_LOC_VALS, ##__VA_ARGS__, STRERROR())

#define INFO(M, ...)      EPRINT(DEBUG_LEVEL("[INFO]  ") DEBUG_LOC_FMT M "\n" DEBUG_LOC_VALS, ##__VA_ARGS__)

#define CHECK(A, M, ...)  BEGIN if (!(A)) { CERROR(M, ##__VA_ARGS__); errno = 0; goto error; } END

// #define SENTINEL(M, ...) BEGIN CERROR(M, ##__VA_ARGS__); errno=0; goto error; END

// #define CHECK_DEBUG(A, M, ...) if(!(A)) { debug(M, ##__VA_ARGS__); errno=0; goto error; }