Add sendAllString function for TcpStream

- The sendAllString function sends the provided string bytes

inc/tcpstream.hpp

 #ifndef _TCPSTREAM_HPP
 #define _TCPSTREAM_HPP
 
+#include <string>
+
 #include "sockaddr.hpp"
 
 /**
@@ -119,6 +121,16 @@ public:
      */
     void sendAll(const void *data, size_t len);
 
+    /**
+     * @brief Send the given string data over the tcp connection. The function 
+     * send all chars of the given string.
+     * 
+     * If the sending fails, an exception is thrown.
+     * 
+     * @param str The string that will be sent.
+     */
+    void sendAllString(const std::string &str);
+
     /**
      * @brief Receive a maximum of len bytes of data from the tcp connection. It 
      * is possible that less than len bytes are received. This call will block 

src/tcpstream.cpp

@@ -113,6 +113,11 @@ void TcpStream::sendAll(const void *data, size_t len)
     }
 }
 
+void TcpStream::sendAllString(const std::string &str)
+{
+    sendAll(str.c_str(), str.size());
+}
+
 ssize_t TcpStream::read(void *data, size_t len)
 {
     if (sockfd == 0)