blob: 118eb0adee90174903b7e3efe357fd4af7bf36f8 (
plain)
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
|
// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_MOVE_H_
#define BASE_MOVE_H_
#pragma once
#include <algorithm>
namespace base {
// The move function provides a functional form of swap to move a swappable
// value leverage the compiler return value optimization and avoiding copy.
//
// The type being moved must have an efficient swap() and be default
// contructable and copyable.
//
// C++0x will contain an std::move() function that makes use of rvalue
// references to achieve the same result. When std::move() is available, it
// can replace base::move().
//
// For example, the following code will not produce any copies of the string.
//
// std::string f() {
// std::string result("Hello World");
// return result;
// }
//
// class Class {
// public:
// Class(std::string x) // Pass sink argument by value
// : m_(move(x)); // Move x into m_
// private:
// std::string m_;
// };
//
// int main() {
// Class x(f()); // the result string of f() is allocated as the temp argument
// // to x() and then swapped into the member m_. No Strings
// // are copied by this call.
// ...
template <typename T> // T models Regular
T move(T& x) { // NOLINT : Non-const ref for standard library conformance
using std::swap;
T result;
swap(x, result);
return result;
}
} // namespace base
#endif // BASE_MOVE_H_
|
