In-depth analysis of C ++ Language Features

C ++, as a language, most people regard it as object-oriented support by default, and think it is an extension of C language, C ++ and C are completely different languages. All the friends who have used the C ++ language think that the C ++ language is indeed a good language.

But sometimes, due to special needs, C ++ has to be used. It is also feasible to implement Thread in C # In C ++, but the code should be slightly complicated:

 
 

  
  
//delegate 0  
  
  
#define DEFINE_DELEGATE(NAME, R)\  
  
  
class NAME##Delegate\  
  
  
{\  
  
  
public:\  
  
  
virtual ~NAME##Delegate(void){ }\  
  
  
virtual R operator()(void) = 0;\  
  
  
};\  
  
  
template\  
  
  
class NAME##DelegateImpl : public NAME##Delegate\  
  
  
{\  
  
  
private:\  
  
  
typedef R (C::*F)(void);\  
  
  
C* m_class;\  
  
  
F m_fun;\  
  
  
public:\  
  
  
NAME##DelegateImpl(C* c, F f){ m_class = c; m_fun = f; }\  
  
  
virtual R operator()(void)\  
  
  
{\  
  
  
if(m_class)\  
  
  
return (m_class-*m_fun)();\  
  
  
}\  
  
  
};\  
  
  
template\  
  
  
NAME##Delegate* Make##NAME##Delegate(C* c, F f)\  
  
  
{\  
  
  
return new NAME##DelegateImpl(c, f);\  
  
  
}  
  
  
//////////////////////////////////////////////////////////////////////////  
  
  
//delegate 1  
  
  
#define DEFINE_DELEGATE(NAME, R, P1)\  
  
  
class NAME##Delegate\  
  
  
{\  
  
  
public:\  
  
  
virtual ~NAME##Delegate(void){ }\  
  
  
virtual R operator()(P1 p1) = 0;\  
  
  
};\  
  
  
template\  
  
  
class NAME##DelegateImpl : public NAME##Delegate\  
  
  
{\  
  
  
private:\  
  
  
typedef R (C::*F)(P1);\  
  
  
C* m_class;\  
  
  
F m_fun;\  
  
  
public:\  
  
  
NAME##DelegateImpl(C* c, F f){ m_class = c; m_fun = f; }\  
  
  
virtual R operator()(P1 p1)\  
  
  
{\  
  
  
if(m_class)\  
  
  
return (m_class-*m_fun)(p1);\  
  
  
}\  
  
  
};\  
  
  
template\  
  
  
NAME##Delegate* Make##NAME##Delegate(C* c, F f)\  
  
  
{\  
  
  
return new NAME##DelegateImpl(c, f);\  
  
  
} 
 
 

This example is relatively simple. The C ++ language is used to implement a function. The client is a client program. There are several methods to send notifications to the client when m_sdk is used for processing. One is sending thread messages, and the other is callback, but the traditional callback does not support object-oriented, which is the starting point for implementing delegate. The following is an implementation: class Delegate

 
 

  
  
DEFINE_DELEGATE (Open, void, int, string)
  
  
Class sdk
  
  
{
  
  
Public:
  
  
OpenDelegate * pEvent;
  
  
Sdk (): pEvent (NULL ){}
  
  
Void Open ()
  
  
{
  
  
Cout
  
  
If (pEvent! = NULL)
  
  
(* PEvent) (100, "hello ");
  
  
}
  
  
};
  
  
Class client
  
  
{
  
  
Private:
  
  
Sdk m_sdk;
  
  
Public:
  
  
Client ()
  
  
{
  
  
M_sdk.pEvent=MakeOpenDelegate(This, OnOpen2 );
  
  
}
  
  
Void Open ()
  
  
{
  
  
M_sdk.Open ();
  
  
}
  
  
Void OnOpen ()
  
  
{
  
  
Cout
  
  
}
  
  
Void OnOpen2 (int t, string str)
  
  
{
  
  
Cout
  
  
}
  
  
};

 
 

1. Differences between standard input implementation methods in C and C ++
2. How does the C ++ compiler allocate storage space for Const constants?
3. Basic Conception and method of C ++ Class Library Design
4. Several Methods for converting C ++ Language
5. How to better compile C ++ code