socket binding won't return an int

问题:

A snippet of my code looks as follows:

int descriptor = socket(AF_INET, SOCK_STREAM, 0);
if(descriptor < 0){
    cerr << "Error establishing socket connection." << endl;
    return -1;
}
int port = 3400;
struct sockaddr_in address;
char buffer[140];
address.sin_family = AF_INET;
address.sin_addr.s_addr = htons(INADDR_ANY);
address.sin_port = htons(port);
int size = sizeof(address);
if(bind(descriptor,(struct sockaddr*)&address,size) < 0){
    cerr << "Error binding socket." << endl;
}
cout << "Waiting for connection on " << INADDR_ANY << " on port " << port << ends;

whenever I try compiling this, I get the following error:

error: invalid operands to binary expression 
('__bind<int &, sockaddr *, int &>' and 'int')
if(bind(descriptor,(struct sockaddr*)&address,size) < 0){

Does anybody know what this could mean? bind() is supposed to return an integer or so I thought. My imports look like this:

#include <iostream>     
#include <string.h>   
#include <string>       
#include <sys/socket.h> 
#include <sys/types.h> 
#include <netinet/in.h>
#include <arpa/inet.h> 
#include <netdb.h>  
#include <unistd.h>
using namespace std;

Thanks!

回答1:

using namespace std; combined with too much header inclusions is likely the culprit here - there's a reason why it has been repeated over and over again here on SO not to use it. By doing that, the compiler sees bind and thinks you mean std::bind from <functional>, not ::bind for sockets. So either do the right thing and review if you really need to include all those headers and get rid of that using declaration, or use ::bind (edit: or both - it's not bad to use :: to indicate you want to use some standard API function from the global namespace)