#include #include #include long lround (double x) { /* Add +/- 0.5 then then round towards zero. */ double tmp = trunc (x + (x >= 0.0 ? 0.5 : -0.5)); if (!isfinite (tmp) || tmp > (double)LONG_MAX || tmp < (double)LONG_MIN) { errno = ERANGE; /* Undefined behaviour, so we could return anything. */ /* return tmp > 0.0 ? LONG_MAX : LONG_MIN; */ } return (long)tmp; }