ronag pimpl helper http://stackoverflow.com/questions/8198236/pimpl-helper-ambiguous-with-inheritence

A.cpp

#include "pimpl_impl.h"
#include "A.h"

template<>
struct pimpl<A>::implementation
{
     void foo()
     {
     }
};

A::A() : pimpl(){}
A::A(const A& other) : pimpl(other){}
A::A(A&& other) : pimpl(std::move(other)){}
A::~A(){}
void A::foo(){impl_->foo();}

A.h

#include "pimpl.h"

struct A : public pimpl<A>
{
    A();
    A(const A& other);
    A(A&& other);
    virtual ~A();
    void foo();
};

main.cpp

#include "A.h"

int main()
{
    A a;
}

Makefile

test: *.cpp | *.h
	g++ -std=c++0x -O0 -g $^ -o $@

pimpl.h

#pragma once
#include <memory>

template<typename T>
class pimpl
{
    template <typename> friend class pimpl;

    pimpl(const pimpl& other);
    pimpl(pimpl&& other);
    pimpl& operator=(const pimpl& other);
    pimpl& operator=(pimpl&& other);    
protected:

    ~pimpl();

    struct implementation;
    std::unique_ptr<implementation> impl_;
public:
    pimpl();

    template<typename P0>
    pimpl(P0&& p0);

    pimpl(const T& other);
    pimpl(T&& other);

    void swap(T& other);
};

pimpl_impl.h

#include "pimpl.h"

template<typename T>
pimpl<T>::pimpl() : impl_(new implementation()){}

template<typename T>
template<typename P0>
pimpl<T>::pimpl(P0&& p0) : impl_(new implementation(std::forward<P0>(p0))){}

template<typename T>
pimpl<T>::~pimpl(){}

template<typename T>
pimpl<T>::pimpl(const T& other) : impl_(new implementation(*((pimpl&)other).impl_)){}

template<typename T>
pimpl<T>::pimpl(T&& other) : impl_(std::move(((pimpl&)other).impl_)){}

template<typename T>
void pimpl<T>::swap(T& other)
{
    impl_.swap(other.impl_);
}