Friends in namespaces

GrahamL

Hi
I have been experimenting with friends and have come across something that I cannot explain

If I declare a class as
@
class MyClass: public QObject
{
Q_OBJECT

public:
friend int main(int,char**);

private:
MyClass(QObject *parent = 0);

};
@

Then I can instantiate a MyClass in main -
@
int main(int argc, char argv[])
{
QApplication a(argc, argv);
MyClass = new MyClass;
raiigui w;
w.show();
return a.exec();
}
@

However, if I place MyClass inside a namespace -
@
namespace MyNamespace
{
class MyClass: public QObject
{
Q_OBJECT

public:
friend int main(int,char**);

private:
MyClass(QObject *parent = 0);
};
}@

I cannot now instantiate MyClass
@
MyNamespace::MyClass mc = new MyNamespace::MyClass;
@

Could anybody explain why this is?

Thanks

SGaist

Hi,

AFAIK you are friending

@int MyNameSpace::main(int, char**)@

And not

@int main(int, char**)@

Out of curiosity, what's your purpose with that friending ?

GrahamL

Hi Thanks for your reply

Placing main inside the same namespace still wont compile!

I am investigating different ways of implementing singletons

SGaist

You can't have main in a namespace

From the c++ standard:
[quote]
3.6.1 Main function [basic.start.main]
1 A program shall contain a global function called main, which is the designated start of the program. It is implementation-defined whether a program in a freestanding environment is required to define a main function. [ Note: In a freestanding environment, start-up and termination is implementation-defined; start- up contains the execution of constructors for objects of namespace scope with static storage duration; termination contains the execution of destructors for objects with static storage duration. — end note ]
[/quote]