Function utf8GetCodePointSize

src/openrct2/core/String.hpp:186–205

* Returns codepoint size or no value if not valid */

     * Returns codepoint size or no value if not valid
     */
    constexpr std::optional<int> utf8GetCodePointSize(std::string_view v)
    {
        if (!v.empty() && !(v[0] & 0x80))
        {
            return { 1 };
        }
        if (v.size() >= 2 && ((v[0] & 0xE0) == 0xC0))
        {
            return { 2 };
        }
        if (v.size() >= 3 && ((v[0] & 0xF0) == 0xE0))
        {
            return { 3 };
        }
        if (v.size() >= 4 && ((v[0] & 0xF8) == 0xF0))
        {
            return { 4 };
        }
        return std::nullopt;
    }

    /**
     * Truncates a string to at most `size` bytes,