c++11: what is its gc interface, and how to implement?

Question

I was watching Bjarne Stroustrup\'s talk \"The Essence of C++\".

In 44:26 he mentioned \"C++11 specifies a GC Interface\".

May I ask what is the interface, a

Answer 1

In addition to the good answer by quantdev, which I've upvoted, I wanted to provide a little more information here (which would not fit in a comment).

Here is a C++11 conforming program which demonstrates whether or not an implementation supports the GC interface:

#include 
#include 

int
main()
{
#ifdef __STDCPP_STRICT_POINTER_SAFETY__
    std::cout << __STDCPP_STRICT_POINTER_SAFETY__ << '\n';
#endif
    switch (std::get_pointer_safety())
    {
    case std::pointer_safety::relaxed:
        std::cout << "relaxed\n";
        break;
    case std::pointer_safety::preferred:
        std::cout << "preferred\n";
        break;
    case std::pointer_safety::strict:
        std::cout << "strict\n";
        break;
    }
}

An output of:

relaxed

means that the implementation has a trivial implementation which does nothing at all.

libc++ outputs:

relaxed

VS-2015 outputs:

relaxed

gcc 5.0 outputs:

prog.cc: In function 'int main()':
prog.cc:10:13: error: 'get_pointer_safety' is not a member of 'std'
    switch (std::get_pointer_safety())
            ^