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
77
|
// checked_cast.h
/**
* Copyright (C) 2015 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/util/assert_util.h"
#include "mongo/util/debug_util.h"
namespace mongo {
/**
* Similar to static_cast, but in debug builds uses RTTI to confirm that the cast
* is legal at runtime.
*/
template<bool>
struct checked_cast_impl;
template<>
struct checked_cast_impl<false> {
template<typename T, typename U>
static T cast(const U& u) {
return static_cast<T>(u);
}
};
template<>
struct checked_cast_impl<true> {
template<typename T, typename U>
static T cast(U* u) {
if (!u) {
return NULL;
}
T t = dynamic_cast<T>(u);
invariant(t);
return t;
}
template<typename T, typename U>
static T cast(const U& u) {
return dynamic_cast<T>(u);
}
};
template<typename T, typename U>
T checked_cast(const U& u) {
return checked_cast_impl<debug>::cast<T>(u);
};
} // namespace mongo
|
