Default Value while 'passing by reference'

[mufasa]

We know C++ supports functions that can carry default values as
follows:

someFunction(in t a, int b, int c =20);

So calling someFunction(x, y) is perfectly legal!

However, if I need to information by reference, can initiate the
referenced variable to a default value?

Eg:

int main()
{
int a = 20;
int b, c;

int &r = a;

someFunction(b, c); // <-------------------- POSSIBLE??
someFunction(b, c,r);//<-------------------- This is allowed

}

someFunction(in t x, int y, int& z = 30); //<-- WELL??
{
}

[Sharad Kala]

Re: Default Value while 'passing by reference'


"mufasa" <soso7df@gmail. com> wrote in message[color=blue]
> We know C++ supports functions that can carry default values as
> follows:
>
> someFunction(in t a, int b, int c =20);
>
> So calling someFunction(x, y) is perfectly legal!
>
> However, if I need to information by reference, can initiate the
> referenced variable to a default value?
>
> Eg:
>
> int main()
> {
> int a = 20;
> int b, c;
>
> int &r = a;
>
> someFunction(b, c); // <-------------------- POSSIBLE??
> someFunction(b, c,r);//<-------------------- This is allowed
>
> }
>
> someFunction(in t x, int y, int& z = 30); //<-- WELL??[/color]

There should be no semicolon at the end
[color=blue]
> {
> }[/color]

This is not legal C++. You are binding a non const reference (z) to a
temporary object, which is illegal. It will work if you bind it to some
l-value.

int a = 30;

void
someFunction(in t x, int y, int& z = a)
{
}

Sharad

[Rolf Magnus]

Re: Default Value while 'passing by reference'

mufasa wrote:
[color=blue]
> We know C++ supports functions that can carry default values as
> follows:
>
> someFunction(in t a, int b, int c =20);
>
> So calling someFunction(x, y) is perfectly legal!
>
> However, if I need to information by reference, can initiate the
> referenced variable to a default value?[/color]

Yes.
[color=blue]
> int main()
> {
> int a = 20;
> int b, c;
>
> int &r = a;
>
> someFunction(b, c); // <-------------------- POSSIBLE??
> someFunction(b, c,r);//<-------------------- This is allowed
>
> }
>
> someFunction(in t x, int y, int& z = 30); //<-- WELL??[/color]

Your function is missing a return type.
[color=blue]
> {
> }[/color]

Make that:

void someFunction(in t x, int y, const int& z = 30); //<-- WELL??
{
}

[Gianni Mariani]

Re: Default Value while 'passing by reference'

mufasa wrote:[color=blue]
> We know C++ supports functions that can carry default values as
> follows:[/color]
....[color=blue]
>
> someFunction(in t x, int y, int& z = 30); //<-- WELL??[/color]

void someFunction(in t x, int y, const int& z = 30)[color=blue]
> {
> }
>[/color]

If you're passing a reference to a literal (30), does it make sense that
you can modify it ? The C++ standard says you can't.

G