I would like to know what #include <tr1/memory> do?

Question

I have this library vesSharedPtr.h which includes the following code:

#ifndef VESSHAREDPTR_H
#define VESSHAREDPTR_H

// C/C++ includes

#include < tr1/memory >

#define vesSharedPtr std::tr1::shared_ptr
#define vesWeakPtr std::tr1::weak_ptr

#endif // VESSHAREDPTR_H

Because when I'm trying to run my project, always appear this error:

#include < tr1/memory > file not found

Answer 1

I encountered this problem when compiling for iOS 7. It works on iOS 6, because the vtk.framework was compiled for iOS 6.