#ifndef EIGEN_STDVECTOR_MODULE_H
#define EIGEN_STDVECTOR_MODULE_H

#include "Core"
#include <vector>

namespace Eigen {

// This one is needed to prevent reimplementing the whole std::vector.
template <class T>
class aligned_allocator_indirection : public aligned_allocator<T>
{
public:
  typedef size_t    size_type;
  typedef ptrdiff_t difference_type;
  typedef T*        pointer;
  typedef const T*  const_pointer;
  typedef T&        reference;
  typedef const T&  const_reference;
  typedef T         value_type;

  template<class U>
  struct rebind
  {
    typedef aligned_allocator_indirection<U> other;
  };

  aligned_allocator_indirection() throw() {}
  aligned_allocator_indirection(const aligned_allocator_indirection& ) throw() : aligned_allocator<T>() {}
  aligned_allocator_indirection(const aligned_allocator<T>& ) throw() {}
  template<class U>
  aligned_allocator_indirection(const aligned_allocator_indirection<U>& ) throw() {}
  template<class U>
  aligned_allocator_indirection(const aligned_allocator<U>& ) throw() {}
  ~aligned_allocator_indirection() throw() {}
};

#ifdef _MSC_VER

  // sometimes, MSVC detects, at compile time, that the argument x
  // in std::vector::resize(size_t s,T x) won't be aligned and generate an error
  // even if this function is never called. Whence this little wrapper.
  #define EIGEN_WORKAROUND_MSVC_STD_VECTOR(T) Eigen::ei_workaround_msvc_std_vector<T>
  template<typename T> struct ei_workaround_msvc_std_vector : public T
  {
    inline ei_workaround_msvc_std_vector() : T() {}
    inline ei_workaround_msvc_std_vector(const T& other) : T(other) {}
    inline operator T& () { return *static_cast<T*>(this); }
    inline operator const T& () const { return *static_cast<const T*>(this); }
    template<typename OtherT>
    inline T& operator=(const OtherT& other)
    { T::operator=(other); return *this; }
    inline ei_workaround_msvc_std_vector& operator=(const ei_workaround_msvc_std_vector& other)
    { T::operator=(other); return *this; }
  };

#else

  #define EIGEN_WORKAROUND_MSVC_STD_VECTOR(T) T

#endif

}

namespace std {

#define EIGEN_STD_VECTOR_SPECIALIZATION_BODY \
  public:  \
    typedef T value_type; \
    typedef typename vector_base::allocator_type allocator_type; \
    typedef typename vector_base::size_type size_type;  \
    typedef typename vector_base::iterator iterator;  \
    explicit vector(const allocator_type& a = allocator_type()) : vector_base(a) {}  \
    template<typename InputIterator> \
    vector(InputIterator first, InputIterator last, const allocator_type& a = allocator_type()) \
    : vector_base(first, last, a) {} \
    vector(const vector& c) : vector_base(c) {}  \
    explicit vector(size_type num, const value_type& val = value_type()) : vector_base(num, val) {} \
    vector(iterator start, iterator end) : vector_base(start, end) {}  \
    vector& operator=(const vector& x) {  \
      vector_base::operator=(x);  \
      return *this;  \
    }

template<typename T>
class vector<T,Eigen::aligned_allocator<T> >
  : public vector<EIGEN_WORKAROUND_MSVC_STD_VECTOR(T),
                  Eigen::aligned_allocator_indirection<EIGEN_WORKAROUND_MSVC_STD_VECTOR(T)> >
{
  typedef vector<EIGEN_WORKAROUND_MSVC_STD_VECTOR(T),
                 Eigen::aligned_allocator_indirection<EIGEN_WORKAROUND_MSVC_STD_VECTOR(T)> > vector_base;
  EIGEN_STD_VECTOR_SPECIALIZATION_BODY

  void resize(size_type new_size)
  { resize(new_size, T()); }

#if defined(_VECTOR_)
  // workaround MSVC std::vector implementation
  void resize(size_type new_size, const value_type& x)
  {
    if (vector_base::size() < new_size)
      vector_base::_Insert_n(vector_base::end(), new_size - vector_base::size(), x);
    else if (new_size < vector_base::size())
      vector_base::erase(vector_base::begin() + new_size, vector_base::end());
  }
  void push_back(const value_type& x)
  { vector_base::push_back(x); }
  iterator insert(iterator position, const value_type& x)
  { return vector_base::insert(position,x); }
  iterator insert(iterator position, size_type new_size, const value_type& x)
  { return vector_base::insert(position, new_size, x); }
#elif defined(_GLIBCXX_VECTOR) && EIGEN_GNUC_AT_LEAST(4,1)
  // workaround GCC std::vector implementation
  // Note that before gcc-4.1 we already have: std::vector::resize(size_type,const T&),
  // no no need to workaround !
  void resize(size_type new_size, const value_type& x)
  {
    if (new_size < vector_base::size())
      vector_base::_M_erase_at_end(this->_M_impl._M_start + new_size);
    else
      vector_base::insert(vector_base::end(), new_size - vector_base::size(), x);
  }
#elif defined(_GLIBCXX_VECTOR)
  using vector_base::resize;
#else
  // default implementation which should always work.
  void resize(size_type new_size, const value_type& x)
  {
    if (new_size < vector_base::size())
      vector_base::erase(vector_base::begin() + new_size, vector_base::end());
    else if (new_size > vector_base::size())
      vector_base::insert(vector_base::end(), new_size - vector_base::size(), x);
  }
#endif

};

}

#endif // EIGEN_STDVECTOR_MODULE_H