#include <iostream>
#include <tcp/tcp_server.hpp>
#include <sstream>

int main(int argc, char** argv)
{
  //initialize default port number and max connection cout
  int port = 12001, max_connection_count= 1000;

  // check if there are any passed arguments
  if(argc > 1)
  {
    // initialize string stream from argument
    std::istringstream arg_stream(argv[1]);

    // bind arguments stream to port int variable if valid
    if ( !(arg_stream >> port) )
      std::cerr << "Invalid number " << argv[1] << '\n';
  }

  // create server instance with specified port number
  TcpServer server(port);

  //start listening to connections
  int result = server.Listen(max_connection_count);
  if(result != 0)
    cout << "Faild to start server !" << std::endl;

  return 0;
}

#include <iostream>
#include <tcp/tcp_server.hpp>
#include <sstream>

int main(int argc, char** argv)
{
  //initialize default port number and max connection cout
  int port = 12001, max_connection_count= 1000;

  // check if there are any passed arguments
  if(argc > 1)
  {
    // initialize string stream from argument
    std::istringstream arg_stream(argv[1]);

    // bind arguments stream to port int variable if valid
    if ( !(arg_stream >> port) )
      std::cerr << "Invalid number " << argv[1] << '\n';
  }

  // create server instance with specified port number
  TcpServer server(port);

  //start listening to connections
  server.Listen(max_connection_count);

  return 0;
}

--- 
+++ 
@@ -22,7 +22,9 @@
   TcpServer server(port);
 
   //start listening to connections
-  server.Listen(max_connection_count);
+  int result = server.Listen(max_connection_count);
+  if(result != 0)
+    cout << "Faild to start server !" << std::endl;
 
   return 0;
 }
Update tcp server demo add error msg
