Can't compile with VS2013, UPDATE4 about restbed HOT 2 CLOSED

 struct SettingsImpl
 {
  public:
    SettingsImpl( )
    {
        m_status_messages = std::map< int, std::string >
        {
            { 100, "Continue" },
            { 101, "Switching Protocols" },
            { 102, "Processing" },
            { 200, "OK" },
            { 201, "Created" },
            { 202, "Accepted" },
            { 203, "Non-Authoritative Information" },
            { 204, "No Content" },
            { 205, "Reset Content" },
            { 206, "Partial Content" },
            { 207, "Multi-Status" },
            { 208, "Already Reported" },
            { 226, "IM Used" },
            { 300, "Multiple Choices" },
            { 301, "Moved Permanently" },
            { 302, "Found" },
            { 303, "See Other" },
            { 304, "Not Modified" },
            { 305, "Use Proxy" },
            { 306, "Reserved" },
            { 307, "Temporary Redirect" },
            { 308, "Permanent Redirect" },
            { 400, "Bad Request" },
            { 401, "Unauthorized" },
            { 402, "Payment Required" },
            { 403, "Forbidden" },
            { 404, "Not Found" },
            { 405, "Method Not Allowed" },
            { 406, "Not Acceptable" },
            { 407, "Proxy Authentication Required" },
            { 408, "Request Timeout" },
            { 409, "Conflict" },
            { 410, "Gone" },
            { 411, "Length Required" },
            { 412, "Precondition Failed" },
            { 413, "Request Entity Too Large" },
            { 414, "Request URI Too Long" },
            { 415, "Unsupported Media Type" },
            { 416, "Requested Range Not Satisfiable" },
            { 417, "Expectation Failed" },
            { 422, "Unprocessable Entity" },
            { 423, "Locked" },
            { 424, "Failed Dependency" },
            { 426, "Upgrade Required" },
            { 428, "Precondition Required" },
            { 429, "Too Many Requests" },
            { 431, "Request Header Fields Too Large" },
            { 500, "Internal Server Error" },
            { 501, "Not Implemented" },
            { 502, "Bad Gateway" },
            { 503, "Service Unavailable" },
            { 504, "Gateway Timeout" },
            { 505, "HTTP Version Not Supported" },
            { 506, "Variant Also Negotiates" },
            { 507, "Insufficient Storage" },
            { 508, "Loop Detected" },
            { 510, "Not Extended" },
            { 511, "Network Authentication Required" }
        };
    }

    uint16_t m_port = 80;
    std::string m_root = "/";
    unsigned int m_worker_limit = 0;
    unsigned int m_connection_limit = 128;
    std::string m_bind_address = "";
    bool m_case_insensitive_uris = true;
    std::map< std::string, std::string > m_properties { };
    std::shared_ptr< const SSLSettings > m_ssl_settings = nullptr;
    std::multimap< std::string, std::string > m_default_headers { };
    std::chrono::milliseconds m_connection_timeout = std::chrono::milliseconds( 5000 );
    std::map< int, std::string > m_status_messages;
};