How to change content of af CString in a const method

[CruelIO]

Hi i have the following method on my objects obj

BOOL obj::CloseRecord() const
{
//Do something

//Empty the member variable m_Id (is a CString)
static_cast<CString>(m_Id) = ""; //<--Doesnt work

//Empty set the member variable m_Item = 0
static_cast<int>(m_Item) = 0; //<---Works fine
}
The var m_Id is never set to "", but continues to have the id value.
How can i clear the m_Id inside a const method?

Thank you

 

[CruelIO]

Hi again

I figured it out! However it might not be the best way. But here goes

CString* aa = (CString*)(&m_Id);
aa->Empty();

 

[cpjust]

You could always make m_Id mutable if you need to change it in a const function.

class obj
{
private:
   [COLOR=blue]mutable[/color] CString m_Id;
...
};

Just use the mutable keyword cautiously and don't overuse it. It should only be used on member variables that don't really affect the state of your object, such as mutexes...

 

[uolj]

const_cast<CString&>(m_Id).Empty();

Although I agree that mutable is probably a better option.