Allocator中uninitialized_fill等函数的简单实现

 1 #ifndef UNINIT_H
 2 #define UNINIT_H
 3 #include <iterator>
 4 
 5 template <typename ForwIter, typename T>
 6 void uninitialized_fill(ForwIter first, ForwIter last, const T &value)
 7 {
 8     typedef typename std::iterator_traits<ForwIter>::value_type VT;
 9     ForwIter save(first);
10     try
11     {
12         for( ; first != end; ++ first)
13             new(static_cast<void *>(&*first))VT(value);
14     }
15 
16     catch(...)
17     {
18         for( ; save != first; ++ save)
19             save->~VT();
20         throw();
21     }
22 }
23 
24 template <typename ForwIter, typename Size, typename T>
25 void uninitialized_fill_n(ForwIter first, Size n, const T &value)
26 {
27     typedef typename std::iterator_traits<ForwIter>::value_type VT;
28     ForwIter save(first);
29     try
30     {
31         for( ; -- n; ++ first)
32             new(static_cast<void *>(&*first))VT(value);
33     }
34     catch(...)
35     {
36         for( ; save != first; ++ save)
37             save->~VT();
38         throw();
39     }
40 
41 }
42 
43 template <typename InputIter, typename ForwIter>
44 void uninitialized_copy(InputIter first, InputIter last; ForwIter dest)
45 {
46     typedef typename std::iterator_traits<ForwIter>::value_type VT;
47     ForwIter save(dest);
48     try
49     {
50         for( ; first != last; ++ first, ++ dest)
51             new(static_cast<void *>(&*dest))VT(*first);
52     }
53     catch(...)
54     {
55         for( ; save != dest; ++ save)
56             save->~VT();
57         throw();
58     }
59 
60 }
61 
62 #endif