1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
|
#include <string>
#include <iostream>
using namespace std;
class Strings
{
std::string *d_memory;
size_t d_size;
size_t d_capacity;
public:
Strings();
~Strings();
void reserve(size_t request);
void append(std::string const &next);
private:
void reserve();
void destroy();
};
Strings::Strings()
:
d_memory(static_cast<string *>(operator new(sizeof(string)))),
d_size(0),
d_capacity(1)
{}
void Strings::reserve(size_t request)
{
if (request <= d_capacity)
return;
do
d_capacity <<= 1;
while (d_capacity < request);
reserve();
}
//RESERVE
void Strings::reserve()
{
using std::string;
string *newMemory = static_cast<string *>( // 1
operator new(d_capacity * sizeof(string)));
for (size_t idx = 0; idx != d_size; ++idx) // 2
new (newMemory + idx) string(d_memory[idx]);
destroy(); // 3
d_memory = newMemory;
}
//=
//APPEND
void Strings::append(std::string const &next)
{
reserve(d_size + 1);
new (d_memory + d_size) std::string(next);
++d_size;
}
//=
Strings::~Strings()
{
destroy();
}
//DESTROY
void Strings::destroy()
{
for (std::string *sp = d_memory + d_size; sp-- != d_memory; )
sp->~string();
operator delete(d_memory);
}
//=
|
