1// Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors
2// Distributed under MIT license, or public domain if desired and
3// recognized in your jurisdiction.
4// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
5
6#ifndef JSON_ALLOCATOR_H_INCLUDED
7#define JSON_ALLOCATOR_H_INCLUDED
8
9#include <cstring>
10#include <memory>
11
12#pragma pack(push, 8)
13
14namespace Json {
15template <typename T> class SecureAllocator {
16public:
17 // Type definitions
18 using value_type = T;
19 using pointer = T*;
20 using const_pointer = const T*;
21 using reference = T&;
22 using const_reference = const T&;
23 using size_type = std::size_t;
24 using difference_type = std::ptrdiff_t;
25
26 /**
27 * Allocate memory for N items using the standard allocator.
28 */
29 pointer allocate(size_type n) {
30 // allocate using "global operator new"
31 return static_cast<pointer>(::operator new(n * sizeof(T)));
32 }
33
34 /**
35 * Release memory which was allocated for N items at pointer P.
36 *
37 * The memory block is filled with zeroes before being released.
38 */
39 void deallocate(pointer p, size_type n) {
40 // memset_s is used because memset may be optimized away by the compiler
41 memset_s(p, n * sizeof(T), 0, n * sizeof(T));
42 // free using "global operator delete"
43 ::operator delete(p);
44 }
45
46 /**
47 * Construct an item in-place at pointer P.
48 */
49 template <typename... Args> void construct(pointer p, Args&&... args) {
50 // construct using "placement new" and "perfect forwarding"
51 ::new (static_cast<void*>(p)) T(std::forward<Args>(args)...);
52 }
53
54 size_type max_size() const { return size_t(-1) / sizeof(T); }
55
56 pointer address(reference x) const { return std::addressof(x); }
57
58 const_pointer address(const_reference x) const { return std::addressof(x); }
59
60 /**
61 * Destroy an item in-place at pointer P.
62 */
63 void destroy(pointer p) {
64 // destroy using "explicit destructor"
65 p->~T();
66 }
67
68 // Boilerplate
69 SecureAllocator() {}
70 template <typename U> SecureAllocator(const SecureAllocator<U>&) {}
71 template <typename U> struct rebind { using other = SecureAllocator<U>; };
72};
73
74template <typename T, typename U>
75bool operator==(const SecureAllocator<T>&, const SecureAllocator<U>&) {
76 return true;
77}
78
79template <typename T, typename U>
80bool operator!=(const SecureAllocator<T>&, const SecureAllocator<U>&) {
81 return false;
82}
83
84} // namespace Json
85
86#pragma pack(pop)
87
88#endif // JSON_ALLOCATOR_H_INCLUDED
89