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c++referenceoverloadinglvalue

How to call 'call by value ' and 'call by reference' overloaded function?

I have two overloaded functions, one "call by value" and the other "call by reference".

int f (int a)
{
    //code
}

int f (int &a)
{
    //code
}

But if I pass const int, it calls the "pass by value" function, why?

const int a=3;
f(a);//calls the call by value function.Why?
Solution

  • Because a is a const int, and so that tells the compiler that you do not wish to modify a. a can't be passed by reference (only by const&), because if it is a reference, f could modify it, but f is not allowed to because a is const.

    So the only overload that is legal is the pass by value one - int f(int a).