C / C++ / MFC

George_George wrote:

Good answer! I have a further question about programming best practice. Do you think it is safe to let the address of the *local* static variable as the return value of a function? Then other part of code (out of this function) will access or even modify the variable by the returned address of the *local* static variable?

Any disadvantages of this approach?

Josh Gray wrote:

I'd say it smells like bad design, the only reason to return a pointer rather than a copy of the int is to allow some other code to modify it. I'd rather provide a method to allow other code to modify the static.

ThatsAlok wrote:

i don't think it bad design.. though it break OOPS basic concept of encapsulation and abstraction!

George_George wrote:

How do you think returning static variable is similar to Singleton pattern

Josh Gray wrote:

I'd rather provide a method to allow other code to modify the static.

George_George wrote:

I am wondering how to modify the value of the static variable from other function (other than from the function in which it is defined)?

George_George wrote:

I think you mean static member of a class. But I mean a static variable defined inside a function.

George_George wrote:

You are right. I am writing a part of the application in C (not C++). I am wondering and willing to listen to your comments and ideas of any disadvantages if I return the address of static variable defined in a function, then let other part of code to access the variable by the returned address.

<br />
int *CPBDialog::TryThis()<br />
{<br />
 static int test;<br />
<br />
	test += 1;<br />
	return &test;<br />
}<br />
<br />
<br />
CErrorOkDlg::CErrorOkDlg(CWnd* pParent /*=NULL*/)<br />
	: CPBDialog(CErrorOkDlg::IDD, pParent)<br />
{<br />
	//{{AFX_DATA_INIT(CErrorOkDlg)<br />
	//}}AFX_DATA_INIT<br />
}<br />
<br />
<br />
BOOL CErrorOkDlg::OnInitDialog() <br />
{<br />
	CPBDialog::OnInitDialog();<br />
<br />
	ModifyStyleEx(0,WS_EX_NODRAG,0);<br />
<br />
	// Sound Beeper<br />
	SoundWarning();<br />
	int *test = TryThis();<br />
	int test2 = *test;<br />
<br />
	return FALSE;<br />
}<br />
<br />
<br />

BadKarma wrote:

This means that when called from multiple threads the behavior will be unpredictable