#pragma once
#include <stdlib.h>
#include <stdio.h>

#define ASSERT(_cond, ...) do {                             \
        if (!(_cond)) {                                     \
            fprintf(stderr, "%s:%d: assertion failed:\n",   \
                    __FILE__, __LINE__);                    \
            fprintf(stderr, __VA_ARGS__);                   \
            fprintf(stderr, "\n");                          \
            exit(1);                                        \
        }                                                   \
    } while (0)

#define ASSERT_NON_NULL(_ptr, _who)                         \
    ASSERT((_ptr) != NULL, "`" _who "' should not be null")

#define UNIMPLEMENTED()                         \
    ASSERT(0, "not implemented")

#define IMPOSSIBLE_(what) \
    ASSERT(0, "unreachable: %s", what)

// hard to explain why this is necessary ...
#define IMPOSSIBLE(x) IMPOSSIBLE_(x)