new

static VALUE
BigDecimal_new(int argc, VALUE *argv, VALUE self)
{
    ENTER(5);
    Real *pv;
    size_t mf;
    VALUE  nFig;
    VALUE  iniValue;

    if (rb_scan_args(argc, argv, "11", &iniValue, &nFig) == 1) {
        mf = 0;
    }
    else {
        mf = GetPositiveInt(nFig);
    }

    switch (TYPE(iniValue)) {
      case T_DATA:
        if (is_kind_of_BigDecimal(iniValue)) {
            pv = VpDup(DATA_PTR(iniValue));
            return ToValue(pv);
        }
        break;

      case T_FIXNUM:
        /* fall through */
      case T_BIGNUM:
        return ToValue(GetVpValue(iniValue, 1));

      case T_FLOAT:
        if (mf > DBL_DIG+1) {
            rb_raise(rb_eArgError, "precision too large.");
        }
        /* fall through */
      case T_RATIONAL:
        if (NIL_P(nFig)) {
            rb_raise(rb_eArgError, "can't omit precision for a Rational.");
        }
        return ToValue(GetVpValueWithPrec(iniValue, mf, 1));

      case T_STRING:
        /* fall through */
      default:
        break;
    }
    SafeStringValue(iniValue);
    GUARD_OBJ(pv, VpNewRbClass(mf, RSTRING_PTR(iniValue),self));

    return ToValue(pv);
}