Question

SockeClient.h file

#define SIZE_OF_BUFFER 4096

class SocketClient {

public:
    SocketClient(int cfd);
    virtual ~SocketClient();

    int recv();
    int getFd();

protected:
    int             m_fd;
    char            *m_buffer;
    vector<char>    m_vbuffer;

};

I was trying to do

vector<char>    m_vbuffer(SIZE_OF_BUFFER);

And I got a syntax error… How do I initialize the vector with size of 4096.
Thanks in advance

Answer 1

Use member-initialization-list, in the constructor’s definition as:

class SocketClient {

public:
    SocketClient(int cfd) : m_vbuffer(SIZE_OF_BUFFER) 
    {                   //^^^^^^^^^^^^^^^^^^^^^^^^^^^ member-initialization-list

         //other code... 
    }


protected:
    int             m_fd;
    char            *m_buffer;
    vector<char>    m_vbuffer;

};

---

You can use member-initialization-list to initialize many members as:

class A
{
  std::string s;
  int a;
  int *p;
  A(int x) : s("somestring"), a(x), p(new int[100])
  {
    //other code if any
  }
 ~A()
  {
     delete []p; //must deallocate the memory!
  }
};