const after function name

[Robert]

Hi all,

class Homer {
public:
int dot(int) const {return 1;}
...
}

what's the meaning of const after function name?

Best regards,
Robert

[Tim Love]

Post by Robert
what's the meaning of const after function name?

Try
http://www-h.eng.cam.ac.uk/help/tpl/languages/C++/argsC++.html

[g***@gmail.com]

Const at the end of function tells the compiler that your function wont
modify any private variables of the class.You can only use these
functions with const objects.

Gevadas A. Akkara

[Christian Meier]

Post by g***@gmail.com
Const at the end of function tells the compiler that your function wont
modify any private variables of the class.You can only use these
functions with const objects.
Gevadas A. Akkara

Not only private members.
const after function name makes the this-pointer const. So you are not
allowed to change a member variable in this function.

Greetings Chris

[Jack Klein]

Post by Christian Meier

Post by g***@gmail.com
Const at the end of function tells the compiler that your function wont
modify any private variables of the class.You can only use these
functions with const objects.
Gevadas A. Akkara

Not only private members.
const after function name makes the this-pointer const. So you are not
allowed to change a member variable in this function.

I hope you mean:

The const keyword after a member function name makes the object *this
constant inside the function.

'this' itself is always constant.

[Dom Gilligan]

Post by Robert
Hi all,
class Homer {
int dot(int) const {return 1;}
...
}
what's the meaning of const after function name?
Best regards,
Robert

'dot' doesn't modify anything in 'Homer'. You'll get warned if you do
try to modify something. Not necessary, but may enable optimisation.

Dom

[Earl Purple]

You won't "warned" you'll get a compiler error.
A const function is also not allowed to:
- Call a non-const member function
- Return by reference any member variable (other than by
const-reference).

A const function may return a member pointer (to non-const).

[Frank Chang]

How about mutable member variables, can they be modified in const
member functions?

[Karl Heinz Buchegger]

Post by Frank Chang
How about mutable member variables, can they be modified in const
member functions?

Yes.

[Jaspreet]

Post by Frank Chang
How about mutable member variables, can they be modified in const
member functions?

Yes they are the 'only' kind of data members that can be modified in a
const member function.