Using boost::asio::io_service as class member field - c++

Question

I have class where I use boost asio library:
Header:
class TestIOService {
public:
void makeConnection();
static TestIOService getInst();
private:
TestIOService(std::string address);
std::string address;
// boost::asio::io_service service;
};
Impl:
#include <boost/asio/ip/address.hpp>
#include <boost/asio/ip/udp.hpp>
#include "TestIOService.h"
void TestIOService::makeConnection() {
boost::asio::io_service service;
boost::asio::ip::udp::socket socket(service);
boost::asio::ip::udp::endpoint endpoint(boost::asio::ip::address::from_string("192.168.1.2"), 1234);
socket.connect(endpoint);
socket.close();
}
TestIOService::TestIOService(std::string address) : address(address) { }
TestIOService TestIOService::getInst() {
return TestIOService("192.168.1.2");
}
And main:
int main(void)
{
TestIOService service = TestIOService::getInst();
service.makeConnection();
}
When I have service defined in makeConnection method with this line:
boost::asio::io_service service;
there is no problem, but when I have it as class field member(commented out in code) I get this error:
note: ‘TestIOService::TestIOService(TestIOService&&)’ is implicitly
deleted because the default definition would be ill-formed:
class TestIOService {

Answer 1

io_service is not copyable.
You can make it shared quickly by wrapping it in shared_ptr<io_service>, but you should really reconsider the design first.
If your class needs to be copyable, it would logically not contain the io_service object
E.g. the following sample does create two instances of the test class not sharing a connection:
Live On Coliru
#include <boost/asio.hpp>
#include <boost/make_shared.hpp>
#include <iostream>
class TestIOService {
public:
void makeConnection();
static TestIOService getInst();
private:
TestIOService(std::string address);
std::string address;
boost::shared_ptr<boost::asio::ip::udp::socket> socket;
boost::shared_ptr<boost::asio::io_service> service;
};
void TestIOService::makeConnection() {
using namespace boost::asio;
service = boost::make_shared<io_service>();
socket = boost::make_shared<ip::udp::socket>(*service);
socket->connect({ip::address::from_string("192.168.1.2"), 1234 });
//socket->close();
}
TestIOService::TestIOService(std::string address)
: address(address) { }
TestIOService TestIOService::getInst() {
return TestIOService("192.168.1.2");
}
int main() {
auto test1 = TestIOService::getInst();
auto test2 = TestIOService::getInst();
}