double integerFromString(const char *buf, int size, int radix) { if (size == 0) return qt_qnan(); double sign = 1.0; int i = 0; if (buf[0] == '+') { ++i; } else if (buf[0] == '-') { sign = -1.0; ++i; } if (((size-i) >= 2) && (buf[i] == '0')) { if (((buf[i+1] == 'x') || (buf[i+1] == 'X')) && (radix < 34)) { if ((radix != 0) && (radix != 16)) return 0; radix = 16; i += 2; } else { if (radix == 0) { radix = 8; ++i; } } } else if (radix == 0) { radix = 10; } int j = i; for ( ; i < size; ++i) { int d = toDigit(buf[i]); if ((d == -1) || (d >= radix)) break; } double result; if (j == i) { if (!qstrcmp(buf, "Infinity")) result = qInf(); else result = qt_qnan(); } else { result = 0; double multiplier = 1; for (--i ; i >= j; --i, multiplier *= radix) result += toDigit(buf[i]) * multiplier; } result *= sign; return result; }
/*! Returns the bit pattern of a quiet NaN as a double. */ Q_CORE_EXPORT double qQNaN() { return qt_qnan(); }