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MSDN const_cast sample

Hello everyone,
In MSDN sample for const_cast,

http://msdn2.microsoft.com/en-us/lib...5h(VS.80).aspx

There is a statement like this,

--------------------
On the line containing the const_cast, the data type of the this
pointer is const CCTest *. The const_cast operator changes the data
type of the this pointer to CCTest *
--------------------

I think in a const member function, like void printNumber() const, the
type of this pointer is const pointer to current type, so we use this
const_cast to remove its const properties.

For a non-const member function, I think this pointer should not be a
const pointer, right?

So, conclusion is,

1. in const member function, this pointer is a const pointer;
2. in non-const member function, this pointer is a non-const pointer.

Right?
thanks in advance,
George
Dec 17 '07 #1
2 2128
George2 wrote:
Hello everyone,
In MSDN sample for const_cast,

http://msdn2.microsoft.com/en-us/lib...5h(VS.80).aspx

There is a statement like this,

--------------------
On the line containing the const_cast, the data type of the this
pointer is const CCTest *. The const_cast operator changes the data
type of the this pointer to CCTest *
--------------------

I think in a const member function, like void printNumber() const, the
type of this pointer is const pointer to current type, so we use this
const_cast to remove its const properties.

For a non-const member function, I think this pointer should not be a
const pointer, right?

So, conclusion is,

1. in const member function, this pointer is a const pointer;
2. in non-const member function, this pointer is a non-const pointer.

Right?
My simple test (which may or may not work in your implementation) seems to
suggest this.

Output is:
class Foo *
class Foo const *

#include <iostream>

class Foo
{
public:
void ShowType() { std::cout << typeid(this).na me() << "\n"; }
void ShowTypeConst() const { std::cout << typeid(this).na me() << "\n"; }
private:
};

int main()
{
Foo Bar;
Bar.ShowType();
Bar.ShowTypeCon st();
}

But, yes, in a const member function, the this* is const.
--
Jim Langston
ta*******@rocke tmail.com
Dec 17 '07 #2
Jim Langston wrote:
[..]

But, yes, in a const member function, the this* is const.
I'd probably say that "the *this is const". I am sure you
meant to dereference the pointer.

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
Dec 17 '07 #3

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