derived members & initializer list

[Aman]

Hi,
Why does the member initialization list not work for derived members
but the assignment within the constructor works fine ?
ex ->
class X{
protected :
short int i ;`
};
class Y: public X{
public :
Y() ;
} ;
Y::Y() : i(10) {} // this gives compilation error
Y::Y() { i = 10 ;} // this works fine .

why is that ?
regards,
Aman .
--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

[White Wolf]

Aman wrote:

Hi,
Why does the member initialization list not work for derived members
but the assignment within the constructor works fine ?
ex ->
class X{
protected :
short int i ;`
};
class Y: public X{
public :
Y() ;
} ;
Y::Y() : i(10) {} // this gives compilation error
Y::Y() { i = 10 ;} // this works fine .

why is that ?

Because those members are initialized by the constructor of the base, you
cannot initialize them again. Only assign.

--
WW aka Attila

[Ron Natalie]

"Aman" <am**@techie.com> wrote in message news:26************************************@mygate .mailgate.org...

Y::Y() : i(10) {} // this gives compilation error
You can only initialize members and your direct base classes.
i is neither, it's a member of your base class.
Y::Y() { i = 10 ;} // this works fine .

This is assignment. i is an accessible base class member and hence
the access is fine.

[Aman Angrish]

gotcha .
Thanks guys.


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

[Agent Mulder]

<Aman>

Hi,
Why does the member initialization list not work for derived members
but the assignment within the constructor works fine ?
ex ->
class X{
protected :
short int i ;`
};
class Y: public X{
public :
Y() ;
} ;
Y::Y() : i(10) {} // this gives compilation error
Y::Y() { i = 10 ;} // this works fine .

why is that ?

</>
class X{
public :
X(int a):i(a){}
protected :
int i;
};
class Y: public X{
public :
Y() ;
} ;
Y::Y() : X(10) {} // fill X::i in initializer of Y through constructor of X
-X