// (C) 2001, Douglas Gregor.
// (C) 2001, Fernando Luis Cacciola Carballal.
//
// This material is provided "as is", with absolutely no warranty expressed
// or implied. Any use is at your own risk.
//
// Permission to use or copy this software for any purpose is hereby granted
// without fee, provided the above notices are retained on all copies.
// Permission to modify the code and to distribute modified code is granted,
// provided the above notices are retained, and a notice that the code was
// modified is included with the above copyright notice.
//
//
#ifndef BOOST_ALIGNED_STORAGE_31AGO2001_HPP
#define BOOST_ALIGNED_STORAGE_31AGO2001_HPP

#include "boost\type_traits\alignment_traits.hpp"

namespace boost {

//
// typename alignment_alias<T>::type
//
// is some built-in type with the same alignment requirements of T.
//
template<class T>
struct alignment_alias
{
  typedef typename
    boost::type_with_alignment<::boost::alignment_of<T>::value>::type
      type ;
} ;


//
// aligned_storage<T, std::size_t Count = 1u>
//
// This template class can be used to acquire storage for an array of
// objects of type T with the alignment requirement of T.
//
// An instance of aligned_storage provides a buffer with the base address
// suitably aligned and with the required size to allocate the array of object of type T.
//
// Instances of aligned_storage can be created on the stack,
// therefore, the following is valid:
//
//    void foo()
//    {
//      aligned_storage<MyClass> buffer ;
//      MyClass Value ;
//      MyClass* ptr = new (buffer.address()) (Value);
//      ptr->foo();
//      ptr->~MyClass() ;
//    }
//
template<class T, std::size_t Count = 1>
class aligned_storage
{
    union dummy_u
    {
      char buffer [ sizeof(T) * Count ] ;
      typename alignment_alias<T>::type alias ;
    } dummy ;

  public :

    T* address() { return reinterpret_cast<T*>(this) ; }
} ;

} // namespace boost


#endif