# [error_01]
# tcp_async_echo_client.cpp:88:83: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
# tcp_async_echo_client.cpp:88:83: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
# /tmp/cc879aYR.o：在函数‘__static_initialization_and_destruction_0(int, int)’中：
# tcp_async_echo_client.cpp:(.text+0x1f2)：对‘boost::system::generic_category()’未定义的引用
# tcp_async_echo_client.cpp:(.text+0x1fe)：对‘boost::system::generic_category()’未定义的引用
# tcp_async_echo_client.cpp:(.text+0x20a)：对‘boost::system::system_category()’未定义的引用
# /tmp/cc879aYR.o：在函数‘boost::system::error_code::error_code()’中：
# tcp_async_echo_client.cpp:(.text._ZN5boost6system10error_codeC2Ev[_ZN5boost6system10error_codeC5Ev]+0x17)：对‘boost::system::system_category()’未定义的引用
# /tmp/cc879aYR.o：在函数‘boost::this_thread::sleep(boost::posix_time::ptime const&)’中：
# tcp_async_echo_client.cpp:(.text._ZN5boost11this_thread5sleepERKNS_10posix_time5ptimeE[_ZN5boost11this_thread5sleepERKNS_10posix_time5ptimeE]+0x28)：对‘boost::this_thread::hiden::sleep_until(timespec const&)’未定义的引用
# /tmp/cc879aYR.o：在函数‘boost::asio::error::get_system_category()’中：
# tcp_async_echo_client.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[_ZN5boost4asio5error19get_system_categoryEv]+0x5)：对‘boost::system::system_category()’未定义的引用
# collect2: error: ld returned 1 exit status
# 解决：
# 装了sudo apt-get install libasio-dev
# 还要装这个sudo apt-get install libboost-all-dev
参考网页：https://blog.csdn.net/tykgls/article/details/6822038
来源：https://blog.csdn.net/ghomeway/article/details/99456601