ZEND_API double zend_u_strtod(const UChar *nptr, UChar **endptr)
{
	const UChar *u = nptr, *nstart;
	UChar c = *u;
	int any = 0;

	while (u_isspace(c)) {
		c = *++u;
	}
	nstart = u;

	if (c == 0x2D /*'-'*/ || c == 0x2B /*'+'*/) {
		c = *++u;
	}

	while (c >= 0x30 /*'0'*/ && c <= 0x39 /*'9'*/) {
		any = 1;
		c = *++u;
	}

	if (c == 0x2E /*'.'*/) {
		c = *++u;
		while (c >= 0x30 /*'0'*/ && c <= 0x39 /*'9'*/) {
			any = 1;
			c = *++u;
		}
	}

	if ((c == 0x65 /*'e'*/ || c == 0x45 /*'E'*/) && any) {
		const UChar *e = u;
		int any_exp = 0;

		c = *++u;
		if (c == 0x2D /*'-'*/ || c == 0x2B /*'+'*/) {
			c = *++u;
		}

		while (c >= 0x30 /*'0'*/ && c <= 0x39 /*'9'*/) {
			any_exp = 1;
			c = *++u;
		}

		if (!any_exp) {
			u = e;
		}
	}

	if (any) {
		char buf[64], *numbuf, *bufpos;
		int length = u - nstart;
		double value;

		if (length < sizeof(buf)) {
			numbuf = buf;
		} else {
			numbuf = (char *) do_alloca(length + 1);
		}

		bufpos = numbuf;

		while (nstart < u) {
			*bufpos++ = (char) *nstart++;
		}

		*bufpos = '\0';
		value = zend_strtod(numbuf, NULL);

		if (numbuf != buf) {
			free_alloca(numbuf);
		}

		if (endptr != NULL) {
			*endptr = (UChar *)u;
		}

		return value;
	}

	if (endptr != NULL) {
		*endptr = (UChar *)nptr;
	}

	return 0;
}