title: Error in `main': free(): invalid pointer (though no free or delete used)
body: <p>I have this simple code that i m trying to run in tutorialspoint.com</p>
  
  <pre><code>#include &lt;iostream&gt;
  
  using namespace std;
  
  class Vehicle {
      string vehicleNo;
      string color;
  
      protected:
      string getVehicleNo()
      {
          return vehicleNo;
      }
  
      string setVehicleNo(string num)
      {
          vehicleNo = num;
      }
  
      string getColor()
      {
          return color;
      }
  
      string setColor(string someColor)
      {
          color = someColor;
      }
  };
  
  class Car: public Vehicle {
      private:
      int distance;
  
      public:
      void setDistance(int a)
      {
          distance = a;
      }
  
      int calculateFare(int)
      {
          return distance * 5;
      }
  
      void displayInformation()
      {
          cout &lt;&lt; distance &lt;&lt; endl; 
      }
  
      void useSetVehicleNo(string num)
      {
          setVehicleNo(num);
      }
  
      string useSetColor(string someColor)
      {
          setColor(someColor);
      }
  
      string useGetVehicleNo()
      {
          return getVehicleNo();
      }
  
      string useGetColor()
      {
          return getColor();
      }
  };
  
  int main()
  {
     //string exit=n;
     string vehicleNo;
     string color;
     Car car;
  
     cout &lt;&lt; "Enter car number : " &lt;&lt; endl;
     cin &gt;&gt; vehicleNo;
     car.useSetVehicleNo(vehicleNo);
  
     cout &lt;&lt; "Enter car color : " &lt;&lt; endl;
     cin &gt;&gt; color;
     car.useSetColor(color);
  
     //vehicleNo = car.useGetColor();
     //color = car.useGetVehicleNo();
  
     //cout &lt;&lt; vehicleNo;
     //cout &lt;&lt; color;
  
  
     return 0;
  }
  </code></pre>
  
  <p>Running this is giving me the following output</p>
  
  <blockquote>
    <p>Enter car number :<br>
    1<br>
    Enter car color :<br>
    g                                                                     </p>
    
    <p><strong>* Error in `main': free(): invalid pointer: 0x00007ff3aa205ba8 *</strong><br>
    ======= Backtrace: =========                                                                                                         /lib64/libc.so.6(+0x7850e)[0x7ff3a969450e]<br>
    /lib64/libc.so.6(cfree+0x5b5)[0x7ff3a96a0165]<br>
    main[0x400e97]<br>
    main[0x400c79]<br>
    /lib64/libc.so.6(__libc_start_main+0xf0)[0x7ff3a963bfe0]<br>
    main[0x400ac9]                                                        </p>
    
    <p>======= Memory map: ========                                                                                                         00400000-00402000 r-xp 00000000 fd:11f 59330668<br>
    /home/cg/roo                                                t/main<br>
    00601000-00602000 r--p 00001000 fd:11f 59330668<br>
    /home/cg/roo                                                t/main<br>
    00602000-00603000 rw-p 00002000 fd:11f 59330668<br>
    /home/cg/roo                                                t/main<br>
    0140c000-0142d000 rw-p 00000000 00:00 0<br>
    [heap]<br>
    7ff3a961c000-7ff3a97d0000 r-xp 00000000 fd:11f 37749826<br>
    /usr/lib64/l<br>
    ibc-2.20.so<br>
    7ff3a97d0000-7ff3a99cf000 ---p 001b4000 fd:11f 37749826<br>
    /usr/lib64/l<br>
    ibc-2.20.so<br>
    7ff3a99cf000-7ff3a99d3000 r--p 001b3000 fd:11f 37749826<br>
    /usr/lib64/l<br>
    ibc-2.20.so<br>
    7ff3a99d3000-7ff3a99d5000 rw-p 001b7000 fd:11f 37749826<br>
    /usr/lib64/l<br>
    ibc-2.20.so<br>
    7ff3a99d5000-7ff3a99d9000 rw-p 00000000 00:00 0<br>
    7ff3a99d9000-7ff3a99ef000 r-xp 00000000 fd:11f 37749844<br>
    /usr/lib64/l<br>
    ibgcc_s-4.9.2-20141101.so.1             7ff3a99ef000-7ff3a9bee000 ---p
    00016000 fd:11f 37749844                  /usr/lib64/l<br>
    ibgcc_s-4.9.2-20141101.so.1<br>
    7ff3a9bee000-7ff3a9bef000 r--p 00015000 fd:11f 37749844<br>
    /usr/lib64/l<br>
    ibgcc_s-4.9.2-20141101.so.1<br>
    7ff3a9bef000-7ff3a9bf0000 rw-p 00016000 fd:11f 37749844<br>
    /usr/lib64/l<br>
    ibgcc_s-4.9.2-20141101.so.1<br>
    7ff3a9bf0000-7ff3a9cf7000 r-xp 00000000 fd:11f 37749280<br>
    /usr/lib64/l<br>
    ibm-2.20.so<br>
    7ff3a9cf7000-7ff3a9ef6000 ---p 00107000 fd:11f 37749280<br>
    /usr/lib64/l<br>
    ibm-2.20.so<br>
    7ff3a9ef6000-7ff3a9ef7000 r--p 00106000 fd:11f 37749280<br>
    /usr/lib64/l<br>
    ibm-2.20.so<br>
    7ff3a9ef7000-7ff3a9ef8000 rw-p 00107000 fd:11f 37749280<br>
    /usr/lib64/l<br>
    ibm-2.20.so<br>
    7ff3a9ef8000-7ff3a9fe8000 r-xp 00000000 fd:11f 37749829<br>
    /usr/lib64/l<br>
    ibstdc++.so.6.0.20<br>
    7ff3a9fe8000-7ff3aa1e8000 ---p 000f0000 fd:11f 37749829<br>
    /usr/lib64/l<br>
    ibstdc++.so.6.0.20<br>
    7ff3aa1e8000-7ff3aa1f0000 r--p 000f0000 fd:11f 37749829<br>
    /usr/lib64/l<br>
    ibstdc++.so.6.0.20<br>
    7ff3aa1f0000-7ff3aa1f2000 rw-p 000f8000 fd:11f 37749829<br>
    /usr/lib64/l<br>
    ibstdc++.so.6.0.20<br>
    7ff3aa1f2000-7ff3aa207000 rw-p 00000000 00:00 0<br>
    7ff3aa207000-7ff3aa228000 r-xp 00000000 fd:11f 37856921<br>
    /usr/lib64/l                                                d-2.20.so 
    7ff3aa412000-7ff3aa417000 rw-p 00000000 00:00 0<br>
    7ff3aa424000-7ff3aa428000 rw-p 00000000 00:00 0<br>
    7ff3aa428000-7ff3aa429000 r--p 00021000 fd:11f 37856921<br>
    /usr/lib64/l                                                d-2.20.so 
    7ff3aa429000-7ff3aa42a000 rw-p 00022000 fd:11f 37856921<br>
    /usr/lib64/l        7ff3aa429000-7ff3aa42a000 rw-p 00022000 fd:11f
    37856921                  /usr/lib64/l<br>
    d-2.20.so<br>
    7ff3aa42a000-7ff3aa42b000 rw-p 00000000 00:00 0<br>
    7fff1dddb000-7fff1ddfc000 rw-p 00000000 00:00 0<br>
    [stack]<br>
    7fff1ddfe000-7fff1de00000 r-xp 00000000 00:00 0<br>
    [vdso]<br>
    ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0<br>
    [vsyscall]                                                  Aborted
    (core dumped)</p>
  </blockquote>