alignedallocator.hh

// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
#ifndef DUNE_ALIGNED_ALLOCATOR_HH
#define DUNE_ALIGNED_ALLOCATOR_HH
 
#include "mallocallocator.hh"
#include <cstdlib>
 
 
namespace Dune
{
 
  template<class T, int Alignment = -1>
  class AlignedAllocator : public MallocAllocator<T> {
 
    /*
     * Check whether an explicit alignment was
     * restricted or fall back to the default alignment of T.
     */
    static constexpr int fixAlignment(int align)
    {
      return (Alignment==-1) ? std::alignment_of<T>::value : Alignment;
    }
 
  public:
    using pointer = typename MallocAllocator<T>::pointer;
    using size_type = typename MallocAllocator<T>::size_type;
    template <class U> struct rebind {
      typedef AlignedAllocator<U,Alignment> other;
    };
 
    static constexpr int alignment = fixAlignment(sizeof(void*));
 
    pointer allocate(size_type n, [[maybe_unused]] const void* hint = 0)
    {
      if (n > this->max_size())
        throw std::bad_alloc();
 
      /*
       * Everybody else gets the standard treatment.
       */
      pointer ret = static_cast<pointer>(std::aligned_alloc(alignment, n * sizeof(T)));
      if (!ret)
        throw std::bad_alloc();
 
      return ret;
    }
  };
 
}
 
#endif // DUNE_ALIGNED_ALLOCATOR_HH