1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef STACK_ALLOCATOR_H
11#define STACK_ALLOCATOR_H
12
13#include <cstddef>
14#include <new>
15
16template <class T, std::size_t N>
17class stack_allocator
18{
19    char buf_[sizeof(T)*N];
20    char* ptr_;
21public:
22    typedef T                 value_type;
23    typedef value_type*       pointer;
24    typedef const value_type* const_pointer;
25    typedef value_type&       reference;
26    typedef const value_type& const_reference;
27    typedef std::size_t       size_type;
28    typedef std::ptrdiff_t    difference_type;
29
30    template <class U> struct rebind {typedef stack_allocator<U, N> other;};
31
32    stack_allocator() : ptr_(buf_) {}
33
34private:
35    stack_allocator(const stack_allocator&);// = delete;
36    stack_allocator& operator=(const stack_allocator&);// = delete;
37
38public:
39    pointer allocate(size_type n, const void* = 0)
40    {
41        if (n > N - (ptr_ - buf_) / sizeof(value_type)) {
42#ifndef _LIBCPP_NO_EXCEPTIONS
43            throw std::bad_alloc();
44#else
45            std::terminate();
46#endif
47        }
48        pointer r = (T*)ptr_;
49        ptr_ += n * sizeof(T);
50        return r;
51    }
52    void deallocate(pointer p, size_type n)
53    {
54        if ((char*)(p + n) == ptr_)
55            ptr_ = (char*)p;
56    }
57
58    size_type max_size() const {return N;}
59};
60
61template <class T, std::size_t N>
62inline
63void
64swap(stack_allocator<T, N>& x, stack_allocator<T, N>& y) {}
65
66#endif  // STACK_ALLOCATOR_H
67