没有匹配调用struct sockaddr_in

Question

I am trying to store the address info for each connection to a UDP server.

I have a sockaddr_in struct for the client:

struct sockaddr_in cli_data;

My goal is to store this struct each time a new client is connected into a vector of structs and use each element of the vector and therefore each respective struct element later on.

I am declaring the vector like that:

std::vector<sockaddr_in> cli_addrlist;

I am then checking whether the recently connected address is present or not, and if it's not - I'm push_back -ing the contents of cli_data to the cli_addrlist struct. This is done by the following lines of code:

1. bool exists = false;
2. while ((n = recvfrom(s, buf, BUF_SIZE, 0, (struct sockaddr *) &cli_data, &len)) != -1) 
3. {
4.    for (int i = 0; i < cli_addrlist.size(); ++i)
5.    {
6.        if (inet_ntoa(cli_addrlist[i].sin_addr) == inet_ntoa(cli_data.sin_addr))
7.        {
8.            exists = true;
9.        }
10.    }
11.    if (exists == false)
12.    {
13.        cli_addrlist.push_back(cli_data());
14.    }      
15. }

The error I'm getting from g++ is:

error: no match for call to '(sockaddr_in) ()'

which is line 13.

I might have missed something very simple, but I just don't seem to get my head around the issue.

Thanks in advance.

Answer 1

由于cli_data是变量，因此您需要通过以下方式使用它：

cli_addrlist.push_back(cli_data); // No parenthesis 

Answer 2

This

cli_addrlist.push_back(cli_data());

should be

cli_addrlist.push_back(cli_data);

Also, make sure this struct is suitable for pushing into vector. Like, if it has pointer members as its data members then it should have copy-constructor/assignment operator corresponding to that.