std_allocator.h

//----------------------------------------------------------------------------//
//                                                                            //
// ozz-animation is hosted at http://github.com/guillaumeblanc/ozz-animation  //
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// Copyright (c) Guillaume Blanc                                              //
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//----------------------------------------------------------------------------//
 
#ifndef OZZ_OZZ_BASE_CONTAINERS_STD_ALLOCATOR_H_
#define OZZ_OZZ_BASE_CONTAINERS_STD_ALLOCATOR_H_
 
#include <new>
 
#include "ozz/base/memory/allocator.h"
 
namespace ozz {
// Define a STL allocator compliant allocator->
template <typename _Ty>
class StdAllocator {
 public:
  typedef _Ty value_type;                     // Element type.
  typedef value_type* pointer;                // Pointer to element.
  typedef value_type& reference;              // Reference to element.
  typedef const value_type* const_pointer;    // Constant pointer to element.
  typedef const value_type& const_reference;  // Constant reference to element.
  typedef size_t size_type;                   // Quantities of elements.
  typedef ptrdiff_t difference_type;  // Difference between two pointers.
 
  StdAllocator() noexcept {}
  StdAllocator(const StdAllocator&) noexcept {}
 
  template <class _Other>
  StdAllocator(const StdAllocator<_Other>&) noexcept {}
 
  template <class _Other>
  struct rebind {
    typedef StdAllocator<_Other> other;
  };
 
  pointer address(reference _ref) const noexcept { return &_ref; }
  const_pointer address(const_reference _ref) const noexcept { return &_ref; }
 
  template <class _Other, class... _Args>
  void construct(_Other* _ptr, _Args&&... _args) {
    ::new (static_cast<void*>(_ptr)) _Other(std::forward<_Args>(_args)...);
  }
 
  template <class _Other>
  void destroy(_Other* _ptr) {
    (void)_ptr;
    _ptr->~_Other();
  }
 
  // Allocates array of _Count elements.
  pointer allocate(size_t _count) noexcept {
    // Makes sure to a use c like allocator, to avoid duplicated constructor
    // calls.
    return reinterpret_cast<pointer>(memory::default_allocator()->Allocate(
        sizeof(value_type) * _count, alignof(value_type)));
  }
 
  // Deallocates object at _Ptr, ignores size.
  void deallocate(pointer _ptr, size_type) noexcept {
    memory::default_allocator()->Deallocate(_ptr);
  }
 
  size_type max_size() const noexcept {
    return (~size_type(0)) / sizeof(value_type);
  }
};
 
// Tests for allocator equality (always true).
template <class _Ty, class _Other>
inline bool operator==(const StdAllocator<_Ty>&,
                       const StdAllocator<_Other>&) noexcept {
  return true;
}
 
// Tests for allocator inequality (always false).
template <class _Ty, class _Other>
inline bool operator!=(const StdAllocator<_Ty>&,
                       const StdAllocator<_Other>&) noexcept {
  return false;
}
}  // namespace ozz
#endif  // OZZ_OZZ_BASE_CONTAINERS_STD_ALLOCATOR_H_