Whats the meaning of this code

[sam]

Hi,
Whats the meaning of this code:-
((CCommunityDlg*)m_pWnd)->OnClose();
I know this is of VC++,
But I just want to know what the logic behiind this cide,
Please givve me solution
Thanks in advance.

 

[Victor Bazarov]

Whats the meaning of this code:-
((CCommunityDlg*)m_pWnd)->OnClose();
I know this is of VC++,
But I just want to know what the logic behiind this cide,

Whatever 'm_pWnd' is, it's being cast to a pointer to 'CCommunityDlg'
and then a member 'OnClose' is called for the object to which that
pointer points after the cast. Same as

CCommunityDlg *pCommunityDlg = (CCommunityDlg*)m_pWnd;
pCommunityDlg->OnClose();

A C-style cast corresponds to either 'static_cast' or 'reinterpret_cast'
or 'const_cast', depending on the declaration of 'm_pWnd' variable.

V

 

[Marcus Kwok]

Whats the meaning of this code:-
((CCommunityDlg*)m_pWnd)->OnClose();

m_pWnd is a pointer of some type. It gets casted (possibly unsafely) to
a pointer to a CCommunityDlg. It then calls the OnClose() method of the
CCommunityDlg class. If m_pWnd is something that can not be safely
converted to a CCommunityDlg*, then it will produce undefined behavior.

 

[Ron Natalie]

Victor Bazarov wrote:
\

A C-style cast corresponds to either 'static_cast' or 'reinterpret_cast'
or 'const_cast', depending on the declaration of 'm_pWnd' variable.

Or const_cast combined with static or reinterpret casts.
Or a protection busting cast for which there is no "new-style" cast
equivelent.