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]

what's the meaning of const after function name?

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

 

[gevadas]

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

 

[Dom Gilligan]

Hi all,

class Homer {
public:
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

 

[Christian Meier]

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

 

[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]

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

Yes.

 

[Jaspreet]

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.

 

[Jack Klein]

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.