提供Boost 1.78.0 time_t_timer.cpp官方源代码示例（C++ 11版）

    //
    // time_t_timer.cpp
    // ~~~~~~~~~~~~~~~~
    //
    // Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
    //
    // Distributed under the Boost Software License, Version 1.0. (See accompanying
    // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
    //