#define SILC_ASSERT(experssion)

    Assert macro that prints error message to stderr and calls abort()
    if the `expression' is false (ie. compares equal to zero).  If
    SILC_DEBUG is not defined this macro has no effect.

    #if defined(SILC_DEBUG)
    #define SILC_ASSERT(expr) assert((expr))
    #else
    #define SILC_ASSERT(expr) do { } while(0)
    #endif /* SILC_DEBUG */