Function , array and pointers

Question

I have a situation where a function can only take "int" (can't change this) and I need it in a different situation. let me directly write the code

bool foo(int dev) 
{
         ...
         ...
      return true/false;
}

I need to pass :

mClassPointer->dev()
mClassPointer[index]->dev()
dev() //(function)
and obviously dev //(variable)

mClassPointer is pointer to class. dev() is a member function of a class , return an Integer.

Thank You, Als for editing I am new here no much familiar with the syntax — Select Call, Mar 02 '12 at 03:24
You do not want to `return true/false;`. Division by zero is undefined. — James McNellis, Mar 02 '12 at 03:24

score 1 · Answer 1 · edited May 23 '17 at 12:12

1

You may be able to do that by changing the argument to a void*.

Be very careful with this and read this thread carefully, espc. the post by Loki Astari:

error: cast from 'void*' to 'int' loses precision

If the function only accepts an int then I don't know if this is possible. Read a discussion in this thread if you are thinking of casting your pointers to int and passing. May not work on certain platforms: Converting a pointer into an integer

edited May 23 '17 at 12:12

Community

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answered Mar 02 '12 at 03:22

Sid

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But he says, 'function can only take "int"'. I'm totally confused about what he's asking. – stinky472 Mar 02 '12 at 03:24
He wants to be able to pass multiple types to a function that takes an int? – stinky472 Mar 02 '12 at 03:25
Hmm, not sure if that is possible without issues. Read this http://stackoverflow.com/questions/153065/converting-a-pointer-into-an-integer – Sid Mar 02 '12 at 03:27
Oh, that seems issue if it does't then need to care anything else not disturb if I change the type? – Select Call Mar 02 '12 at 03:41
@SelectCall not sure what you mean? – Sid Mar 02 '12 at 03:44
@SelectCall just out of curiosity, what is your native language? – stinky472 Mar 02 '12 at 03:52

score 1 · Accepted Answer · answered Mar 02 '12 at 03:24

1

If you have a function that needs to handle different datatypes in different situations (as is vaguely implied in your question), then perhaps you need to look into templates.

answered Mar 02 '12 at 03:24

Alex Z

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+1 for how to make the function really generic. I don't really know if that's what he meant or if there's some weird restriction that only allows him to accept integers. – stinky472 Mar 02 '12 at 03:29
Please elaborate I have a situation where I can take only "int" value – Select Call Mar 02 '12 at 03:34
@SelectCall Could you elaborate as to your question? We're not sure what you want to do or why. – stinky472 Mar 02 '12 at 03:38
@SelectCall What other *types* do you want the function to take? Your question isn't clear enough there. Theoretically using a template can allow any type to be used... provided it doesn't break the code the template is used in – Alex Z Mar 02 '12 at 03:40
I have couple of device which I need to support , to validate the device I have been calling function at different places which takes above listed arguments . till now It has only "int" now as I am modifying further requires it to handle all I wanna make function generic – Select Call Mar 02 '12 at 03:48
If you want to employ generic functions while staying strictly C++, then templates are a much safer bet over using a void*. I'd suggest you follow the link I provided and learn about them. – Alex Z Mar 02 '12 at 03:57
Alex, can we have other option to do the same thing or other proposal for new funcation? – Select Call Mar 02 '12 at 04:23
Sorry, not sure what you mean there...could you elaborate? – Alex Z Mar 02 '12 at 04:28

Function , array and pointers

2 Answers2