C++ build error

[Pasto]

void SampleFun(int&);
void SampleFun1(int&);
void TestFun(int*);
void main()
{

int x = 500;
int*y;
y = &x;
TestFun(y);
}
void TestFun(int* a)
{
SampleFun((int)*a);
SampleFun1((int&)*a);
}
void SampleFun(int& val)
{
val= 1000;
}
void SampleFun1(int& val)
{
val= 22222;
}


SampleFun((int)*a); is not working in linux
SampleFun1((int&)*a); is ok

but both are working in windows


Thanks in advance

[darkrose0510]

C++ Language Tutorial

[KenJackson]

This is a value: (int)*a
You are trying to pass it by reference.

Are you saying a windows C++ compiler compiles that without an error? Which compiler?

BTW, if you click on the asterisk, #, you'll get a pair of code tags. If you put your code between them it will look a lot nicer and will make it easier for people to help you.

[Pasto]

Hai KenJackson,

Iam using visual studio 2008. Why it doesnt give any error,

As you said (int)*a is value, then what is (int&)*a .


Thank you for the comments....

[KenJackson]

(int&)*a is a reference to the object that a points to.

Apparently what Visual C++ is doing is making a local copy of the value and passing a reference to it to function SampleFun(). That would obviously work, but it could circumvent the intent since data is often passed by reference so that it can be modified. If you modify a temporary copy, the change is lost when the function returns.

Let me put in a plug against ever using "&" in a declaration. I wish it were not part of the language.

When you look at a call to SampeFun(), you don't know that it is passing by reference unless you look a the declaration, which could be in some header that's buried by multiple inclusions. And if it modifies a variable that you though you were passing by value, you have a bug.