#ifndef MYCLASS_HPP
#define MYCLASS_HPP
class MyClass
{
struct PImpl;
PImpl *m_pimpl;
public:
MyClass(); 
~MyClass();
};

#endif // MYCLASS_HPP

#include "MyClass.hpp"
#include <vector>
struct MyClass::PImpl
{
std::vector<int> data;
};
MyClass::MyClass()
:
m_pimpl(new PImpl)
{
//// try to access m_pimpl using completion here
//// m_pimpl->data CRASH
}
MyClass::~MyClass()
{
delete m_pimpl;
}