Re: C++ mapping of OUT variable-length structures

[ERDI Gergo <cactus cactus rulez org>]

On Wed, 24 Apr 2002, Diego Sevilla Ruiz wrote:

> | So this is useful when you pass in (on the caller side) a non-empty
> | structure, right?
> 
> Hmmm... I can't understand what you mean by a non-empty structure...
> This has nothing to do with either if the structure is empty or
> non-empty... (and I don't see the need for an empty structure either...)

OK so let's talk about actual code here.

Suppose I have the following on the client side:

	Test::Test_st *strct;
	master_ptr->foo (strct);
	// Do stuff on strct
	delete strct;

The signature of foo is, according to this _out convention:

	void foo (Test::Test_st_out struct_out);

So in the above example, when master_ptr->foo returns, struct_out points
to a valid structure, right?

So, what happens when instead, the following is done:

	Test::Test_st *strct = new Test::Test_st;
	// Fill strct
	// Use it as an IN parameter
	other_ptr->other_method (*strct);
		
	master_ptr->foo (strct);

	delete strct;

Will master_ptr->foo in this case delete the old strct first? Or is this
simply something that shouldn't be done? If it shouldn't be done, then I,
again, don't understand what the _out class is supposed to do: you could
use vanilla Test::Test_st*&'s as the OUT argument type and do the same.


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