New C++11 main function.

[Zerpent]

Hi I am currently trying C++11 in VS2013.

I got a bit suprised when I saw the following main function:

#include "stdafx.h"
#include <iostream>
#include <thread>
#include <array>
#include <cstdlib>
#include <string>

void task1()
{
	std::cout << "Hello world!" << std::endl;
}

int main(std::array<System::String ^> ^args)
{
	std::cout << "Hello world" << std::endl;
	std::thread thread_1(task1);
	thread_1.join();
	return 0;
}

When I try to compile this, it complains that System and String are not declared. How do you do to make the main function work? Is the array syntax right?

[Catfish4]

This is not standard C++.
It is C++/CLI (which is C++ with Microsoft "improvements").

http://en.wikipedia.org/wiki/C%2B%2B/CLI
http://www.codeproject.com/Articles/19354/Quick-C-CLI-Learn-C-CLI-in-less-than-10-minutes

[Zerpent]

I see :). I changed back to the standard main()-function. Now it works.

Thank you.

[vlad from moscow]

It seems that this code is invalid.

int main(std::array<System::String ^> ^args)

I think that instead of std::array which requires two template arguments there should be CLR array. That is the valid code should look as

int main(array<System::String ^> ^args)

[Stewbond]

While we're on the subject of standard C++, I've always had the question about Qt. It's pretty common to use:

class SomeClass : QSomeOtherClass
{
private slots: 
   someSlot();
};

private slots: doesn't seem like standard C++, but is there perhaps a provision in the standard which allows for for specific tags to go with private/protected/public statements?

[Catfish4]

private slots: doesn't seem like standard C++

Vlad, what does the standard say about this? (I know, I'm very lazy.)

[JLBorges]

Qt has #define slots in some header; so to the cpmpiler, the translation unit looks like:

class SomeClass : QSomeOtherClass
{
private slots: 
   someSlot();
};

The token slots is used by the meta object compiler to generate extra code (for signal definitions). Qt is riddled with horrible kludges of this kind; probably written long ago, before meta-programming became mainstream C++.

[Stewbond]

Cool thanks