moon.new_service这个api是怎么获得服务id并返回的? 看了好久也没有捋清楚. math.tointeger(co_yield()) 不是应该挂起当前协程么?

我写了个例子, 我理解的是moon.new_service 执行完都需要再次执行coroutine.resume才能把for循环跑完. 因为new_service最后yield的了? 但是实际是for循环是一次都执行完了,并没有中途挂起, 而且返回了服务id. 一直也没有看懂这服务id怎么来的. 求帮忙讲解一下.

moon.async(function()
    local conf = {
        base_name = "gate",
        file = "service_gate.lua",
        host = "0.0.0.0",
        base_port = 20520,
        num = 5,
        unique = true, -- 通过name做唯一区分,name不能相同
    }

    for i = 1, conf.num do
        conf.port = conf.base_port + i - 1
        conf.name = conf.base_name .. i
        local r = moon.new_service("lua", conf)
    end
end)

我结合hello world例程和mysql例程写了一个测试使用mysql例程. 功能简单, 若接收到客户端发来的指定字符串'dbtest' 就从mydb中查询所有表名, 其结果直接发送给客户端作为回复. 代码如下 报错如下:

1. 在on message里直接写mysql连接查询 就会报错, 所以只能在协程里写.
2. 在协程中写, 本框架不能使用全局变量, 所以函数必须传参. 这种情况下该怎么传参到匿名函数中? 卡了很久了, 网上搜不到, lua的pdf我也下了看, 但我还是不知道这种该怎么写, 求助一下.

gcc version 12.2.0 编译有报错

lua_json.cpp In file included from ../../../lualib-src/lua_json.cpp:6: ../../../common/buffer.hpp: In constructor ‘moon::base_buffer::base_buffer(moon::base_buffer&&)’: ../../../common/buffer.hpp:166:26: error: ‘exchange’ is not a member of ‘std’ 166 | , flag_(std::exchange(other.flag_, 0)) | ^~~~~~~~ ../../../common/buffer.hpp:167:34: error: ‘exchange’ is not a member of ‘std’ 167 | , headreserved_(std::exchange(other.headreserved_, 0)) | ^~~~~~~~ ../../../common/buffer.hpp:168:30: error: ‘exchange’ is not a member of ‘std’ 168 | , capacity_(std::exchange(other.capacity_, 0)) | ^~~~~~~~ ../../../common/buffer.hpp:169:29: error: ‘exchange’ is not a member of ‘std’ 169 | , readpos_(std::exchange(other.readpos_, 0)) | ^~~~~~~~ ../../../common/buffer.hpp:170:30: error: ‘exchange’ is not a member of ‘std’ 170 | , writepos_(std::exchange(other.writepos_, 0)) | ^~~~~~~~ ../../../common/buffer.hpp:171:26: error: ‘exchange’ is not a member of ‘std’ 171 | , data_(std::exchange(other.data_, nullptr)) | ^~~~~~~~ ../../../common/buffer.hpp: In member function ‘moon::base_buffer& moon::base_buffer::operator=(moon::base_buffer&&)’: ../../../common/buffer.hpp:180:30: error: ‘exchange’ is not a member of ‘std’ 180 | flag_ = std::exchange(other.flag_, 0); | ^~~~~~~~ ../../../common/buffer.hpp:181:38: error: ‘exchange’ is not a member of ‘std’ 181 | headreserved_ = std::exchange(other.headreserved_, 0); | ^~~~~~~~ ../../../common/buffer.hpp:182:34: error: ‘exchange’ is not a member of ‘std’ 182 | capacity_ = std::exchange(other.capacity_, 0); | ^~~~~~~~ ../../../common/buffer.hpp:183:33: error: ‘exchange’ is not a member of ‘std’ 183 | readpos_ = std::exchange(other.readpos_, 0); | ^~~~~~~~ ../../../common/buffer.hpp:184:34: error: ‘exchange’ is not a member of ‘std’ 184 | writepos_ = std::exchange(other.writepos_, 0); | ^~~~~~~~ ../../../common/buffer.hpp:185:30: error: ‘exchange’ is not a member of ‘std’ 185 | data_ = std::exchange(other.data_, nullptr); | ^~~~~~~~ make[1]: *** [Makefile:182: ../../obj/lualib/Debug/lua_json.o] Error 1 make: *** [Makefile:75: lualib] Error 2