Copy constructor question

[Bart Simpson]

I have a class that has a member that is a const reference:

class MyClass
{
public:
MyClass(const AnotherClass& ac);
MyClass(const MyClass& mc);
//....

private:
const AnotherClass &m_reference ;
};


How do I implement the copy constructor? (I get compilation erros with
this):

MyClass::MyClass(const MyClass& mc)
:m_reference(mc.m_reference)
{
//..
Copy();
}

Compiler error: Error error C3646: 'm_reference' : unknown override
specifier

 

[Zeppe]

I have a class that has a member that is a const reference:

class MyClass
{
public:
MyClass(const AnotherClass& ac);
MyClass(const MyClass& mc);
//....

private:
const AnotherClass &m_reference ;
};


How do I implement the copy constructor? (I get compilation erros with
this):

you can't.

Use a pointer instead of a reference if you want to copy the object
properly (i.e., modifying the reference member).

Regards,

Zeppe

 

[Victor Bazarov]

you can't.

Use a pointer instead of a reference if you want to copy the object
properly (i.e., modifying the reference member).

Huh? Compile this (and then explain):

class Foo {};
class Bar {
Foo const & foo;
public:
Bar(Bar const& b) : foo(b.foo) {}
Bar(Foo const& f) : foo(f) {}
};

int main() {
Foo foo;
Bar bar(foo);
Bar barbar(bar);
}

V

 

[Zeppe]

Huh? Compile this (and then explain):

Sorry, sorry! Gosh! I was reading the post, and then I just saw the
reference member and I suddenly thought about the operator=... stupid
me, I have no excuse, I should really pay attention before posting. Even
because my sentence was totally unrelated to the error...

To the OP: the code seems fine to me, in which line are you experiencing
the error? It seems the effect of some Microsoft extension (CLR)...

Regards,

Zeppe

 

[Victor Bazarov]

[..]
To the OP: the code seems fine to me, in which line are you
experiencing the error? It seems the effect of some Microsoft
extension (CLR)...

Did you miss the OP's explanation? It was a missing colon in

Blah(const Boo& boo) m_boo(boo) {}

instead of needed

Blah(const Boo& boo) : m_boo(boo) {}



V

 

[Zeppe]

[..]
To the OP: the code seems fine to me, in which line are you
experiencing the error? It seems the effect of some Microsoft
extension (CLR)...

Did you miss the OP's explanation? It was a missing colon in

Blah(const Boo& boo) m_boo(boo) {}

instead of needed

Blah(const Boo& boo) : m_boo(boo) {}



V

Yeah, the funny thing is, the code he posted in the ng was correct.
Quite hard for anybody to find the error

Regards,

Zeppe

 

[James Kanze]

I have a class that has a member that is a const reference:

class MyClass
{
public:
MyClass(const AnotherClass& ac);
MyClass(const MyClass& mc);
//....

private:
const AnotherClass &m_reference ;
};

How do I implement the copy constructor? (I get compilation erros with
this):

MyClass::MyClass(const MyClass& mc)
:m_reference(mc.m_reference)
{
//..
Copy();
}

Compiler error: Error error C3646: 'm_reference' : unknown override
specifier

With what compiler? It looks fine to me, and compiles without
error or warning with g++ (4.1.0), Sun CC (5.8) and VC++ (8).

 

[James Kanze]

[..]
To the OP: the code seems fine to me, in which line are you
experiencing the error? It seems the effect of some Microsoft
extension (CLR)...

Did you miss the OP's explanation? It was a missing colon in

Blah(const Boo& boo) m_boo(boo) {}

instead of needed

Blah(const Boo& boo) : m_boo(boo) {}

No it wasn't. I copy/pasted the code directly from his message,
and compiled it successfully with three different compilers. So
either he's using some strange options (or a compiler I don't
have access to), as Zeppe suggests, or the code he posted isn't
the code causing the problem.

 

[Victor Bazarov]

[..]
To the OP: the code seems fine to me, in which line are you
experiencing the error? It seems the effect of some Microsoft
extension (CLR)...

Did you miss the OP's explanation? It was a missing colon in

Blah(const Boo& boo) m_boo(boo) {}

instead of needed

Blah(const Boo& boo) : m_boo(boo) {}

No it wasn't.

Yes, it was. Go read the OP's explanation before arguing again.

I copy/pasted the code directly from his message,

I wasn't talking of the code posted. I was talking about the
explanation the OP gave about the error. Jeez, are you just here
to argue for the sake of disagreeing?

and compiled it successfully with three different compilers. So
either he's using some strange options (or a compiler I don't
have access to), as Zeppe suggests, or the code he posted isn't
the code causing the problem.

V