Simpl shared_ptr declaration

Hi,

I did a search but all I found were topics too advanced for me to understand. I would like to simply declare a shared_ptr and know what includes I need to do it. I've seen some people use boost:: and some use std::tr1 which confuses me as I've never heard of boost or tr1 and I hear raw pointers are on the way out from modern code so I need to learn to use smart ones.

Can anyone help? I tried:

Code:

---

#include <memory>

int main ()
{
    std::shared_ptr<int> myPointer;

    return 1;
}

---

But my compiler rejected it. ANy ideas? Thanks so much.

Chris

At the moment, shared_ptr is not part of the C++ standard, although it is expected to be in the next version of the C++ standard. However, it is part of the Technical Report 1 (TR1) extensions to the C++ standard library. As such, you should write:

Code:

---

#include <memory>

int main()
{
    std::tr1::shared_ptr<int> myPointer;
    // ...
}

---

This assumes that you are using a standard library implementation that has support for TR1. If not, this will probably fail to compile.

Now, shared_ptr was developed for the Boost C++ Libraries, which serves as a kind of "breeding ground" for libraries that may eventually be included in the C++ standard library. This explains why there is boost::shared_ptr. If it turns out that you are unable to use TR1, then one place to find a TR1 implementation is Boost.

That's great thanks. I still get the compile error but at least now thanks to you I know why. I think I need to do a bit of research on how to get my IDE to use the boost library. My present stuff doesn't have the shared_ptr under TR1 if that makes sense :)

Hi I've installed boost but my IDE won't recognise the files it calls:

Code:

---

#include <boost/lambda/lambda.hpp>
#include <iostream>
#include <iterator>
#include <algorithm>

int main()
{
    using namespace boost::lambda;
    typedef std::istream_iterator<int> in;

    std::for_each(
        in(std::cin), in(), std::cout << (_1 * 3) << " " );
}

---

I don't really understand the code but I can understand files and include stuff. In my compiler settings I have the boost subdir in my search directories but it still can't find the stuff. Any ideas? Thanks to anyone who replies.

My guess is that you did not add the Boost source directory to your compiler's list of directories to search for header files.

That's exactly what i thought. I checked it out though seems ok:

C:\Program Files\boost\boost_1_44_0\boost

That's where they all are. Ah no matter if I can't do it, teachs me for being a n00b! Thanks anyway mate.

P.S. it's fixed. I had overrun the include path by one *boost* too many! The path should've stopped at:

C:\Program Files\boost\boost_1_44_0

instead I had it at

C:\Program Files\boost\boost_1_44_0\boost

Whoops!