dcsimg
Login | Register   
LinkedIn
Google+
Twitter
RSS Feed
Download our iPhone app
TODAY'S HEADLINES  |   ARTICLE ARCHIVE  |   FORUMS  |   TIP BANK
Browse DevX
Sign up for e-mail newsletters from DevX

By submitting your information, you agree that devx.com may send you DevX offers via email, phone and text message, as well as email offers about other products and services that DevX believes may be of interest to you. DevX will process your information in accordance with the Quinstreet Privacy Policy.


Tip of the Day
Language: C++
Expertise: Beginner
Feb 14, 2000

WEBINAR:

On-Demand

Building the Right Environment to Support AI, Machine Learning and Deep Learning


Pointers to Class Member Functions

Question:
I'm trying to write a program that has a pointer to a private member function of a class. A public member function calls some of the private functions by using this pointer. I'm using a typedef for the pointer. The typedef is:
typedef void (pvm_em::*code_ptr)(int,int);
where pvm_em is the name of my class. I'm making an array of these pointers as follows:
code_ptr instructions[29];
and I'm filling this array by using statements that look like:
instructions[1] = &pvm_em::mov;
All of the code I've mentioned up to this point seems to work just fine, but I get a compiler error when I use the following line of code:
(this.instructions)[opcode](arg1, arg2);
I've tried several different ways of writing this line of code (with and without the This pointer and trying to dereference the pointer), but I can't seem to get it to work. I get errors saying I must use the ".*" or "->*" operators. What are these operators, and what is the syntax for using them?

Answer:
You almost got it right. Try the following:

(this->*instructions[opcode])(arg1, arg2);
DevX Pro
 
Comment and Contribute

 

 

 

 

 


(Maximum characters: 1200). You have 1200 characters left.

 

 

Sitemap
Thanks for your registration, follow us on our social networks to keep up-to-date