Function to_string

src/string_util.cpp:51–70

We need well defined results that don't depend on locale

	// We need well defined results that don't depend on locale
	std::array<char, 4 + std::numeric_limits<std::int64_t>::digits10>
		to_string(std::int64_t const n)
	{
		std::array<char, 4 + std::numeric_limits<std::int64_t>::digits10> ret;
		char *p = &ret.back();
		*p = '\0';
		// we want "un" to be the absolute value
		// since the absolute of INT64_MIN cannot be represented by a signed
		// int64, we calculate the abs in unsigned space
		std::uint64_t un = n < 0
			? std::numeric_limits<std::uint64_t>::max() - std::uint64_t(n) + 1
			: std::uint64_t(n);
		do {
			*--p = '0' + un % 10;
			un /= 10;
		} while (un);
		if (n < 0) *--p = '-';
		std::memmove(ret.data(), p, std::size_t(&ret.back() - p + 1));
		return ret;
	}

	bool is_alpha(char c)
	{