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
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
/* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
Copyright (C) 2005, 2006 StatPro Italia srl
This file is part of QuantLib, a free-software/open-source library
for financial quantitative analysts and developers - http://quantlib.org/
QuantLib is free software: you can redistribute it and/or modify it
under the terms of the QuantLib license. You should have received a
copy of the license along with this program; if not, please email
<quantlib-dev@lists.sf.net>. The license is also available online at
<http://quantlib.org/license.shtml>.
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 license for more details.
*/
/*! \file observablevalue.hpp
\brief observable and assignable proxy to concrete value
*/
#ifndef quantlib_observable_value_hpp
#define quantlib_observable_value_hpp
#include <ql/patterns/observable.hpp>
namespace QuantLib {
//! %observable and assignable proxy to concrete value
/*! Observers can be registered with instances of this class so
that they are notified when a different value is assigned to
such instances. Client code can copy the contained value or
pass it to functions via implicit conversion.
\note it is not possible to call non-const method on the
returned value. This is by design, as this possibility
would necessarily bypass the notification code; client
code should modify the value via re-assignment instead.
*/
template <class T>
class ObservableValue {
public:
ObservableValue();
ObservableValue(const T&);
ObservableValue(const ObservableValue<T>&);
//! \name controlled assignment
//@{
ObservableValue<T>& operator=(const T&);
ObservableValue<T>& operator=(const ObservableValue<T>&);
//@}
//! implicit conversion
operator T() const;
operator boost::shared_ptr<Observable>() const;
//! explicit inspector
const T& value() const;
private:
T value_;
boost::shared_ptr<Observable> observable_;
};
// template definition
template <class T>
ObservableValue<T>::ObservableValue()
: value_(), observable_(new Observable) {}
template <class T>
ObservableValue<T>::ObservableValue(const T& t)
: value_(t), observable_(new Observable) {}
template <class T>
ObservableValue<T>::ObservableValue(const ObservableValue<T>& t)
: value_(t.value_), observable_(new Observable) {}
template <class T>
ObservableValue<T>& ObservableValue<T>::operator=(const T& t) {
value_ = t;
observable_->notifyObservers();
return *this;
}
template <class T>
ObservableValue<T>&
ObservableValue<T>::operator=(const ObservableValue<T>& t) {
value_ = t.value_;
observable_->notifyObservers();
return *this;
}
template <class T>
ObservableValue<T>::operator T() const {
return value_;
}
template <class T>
ObservableValue<T>::operator boost::shared_ptr<Observable>() const {
return observable_;
}
template <class T>
const T& ObservableValue<T>::value() const {
return value_;
}
}
#endif
|
