std::string system_message(int sys_err_code)
{
/**/
}

const char* thread_exception::message() const
{
    if (m_sys_err != 0)
        return system_message(m_sys_err).c_str();
    return what();
}

ЮЖ>std::string system_message(int sys_err_code)
ЮЖ>{
ЮЖ>/**/
ЮЖ>}

ЮЖ>const char* thread_exception::message() const
ЮЖ>{
ЮЖ>    if (m_sys_err != 0)
ЮЖ>        return system_message(m_sys_err).c_str();
ЮЖ>    return what();
ЮЖ>}
ЮЖ>

std::string system_message(int sys_err_code)
{
    std::string str;
# ifdef BOOST_WINDOWS
    LPVOID lpMsgBuf;
    ::FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
        FORMAT_MESSAGE_FROM_SYSTEM |
        FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL,
        sys_err_code,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
        (LPSTR)&lpMsgBuf,
        0,
        NULL);
    str += static_cast<LPCSTR>(lpMsgBuf);
    ::LocalFree(lpMsgBuf); // free the buffer
    while (str.size() && (str[str.size()-1] == '\n' ||
               str[str.size()-1] == '\r'))
    {
        str.erase(str.size()-1);
    }
# else
    str += std::strerror(errno);
# endif
    return str;
}

Please, please, please fix this!