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1[/
2Copyright 2019 Glen Joseph Fernandes
3(glenjofe@gmail.com)
4
5Distributed under the Boost Software License, Version 1.0.
6(http://www.boost.org/LICENSE_1_0.txt)
7]
8
9[section:nvp nvp]
10
11[section Overview]
12
13The header <boost/core/nvp.hpp> provides the class template `boost::nvp` that
14pairs a name (`const char*`) with the address of a value (`T*`). It is the new
15implementation of the NVP type previously provided by the Boost Serialization
16library. This type now lives in the Core library so that other Boost libraries
17can support named value serialization without taking a dependency on the
18Serialization library.
19
20[endsect]
21
22[section Examples]
23
24The following snippet shows use in a member serialize function:
25
26```
27template<class A>
28void serialize(A& archive, unsigned)
29{
30    archive & boost::make_nvp("x", x_) & boost::make_nvp("y", y_);
31}
32```
33
34[endsect]
35
36[section Reference]
37
38```
39namespace boost {
40
41template<class T>
42class nvp {
43public:
44    nvp(const char* name, T& value) noexcept;
45
46    const char* name() const noexcept;
47
48    T& value() const noexcept;
49
50    const T& const_value() const noexcept;
51};
52
53template<class T>
54const nvp<T> make_nvp(const char* name, T& value) noexcept;
55
56} /* boost */
57
58#define BOOST_NVP(object) ``['see below]``
59```
60
61[section Constructors]
62
63[variablelist
64[[`nvp(const char* name, T& value) noexcept;`]
65[Initializes the stored name pointer with `name` and the value pointer with
66`addressof(value)`.]]]
67
68[endsect]
69
70[section Members]
71
72[variablelist
73[[`const char* name() const noexcept;`]
74[Returns a pointer to the name.]]
75[[`T& value() const noexcept;`]
76[Returns a reference to the value.]]
77[[`const T& const_value() const noexcept;`]
78[Returns a reference to the value.]]]
79
80[endsect]
81
82[section Functions]
83
84[variablelist
85[[`template<class T> const nvp<T> make_nvp(const char* name, T& value)
86noexcept;`]
87[Returns `nvp<T>(name, value)`.]]]
88
89[endsect]
90
91[section Macros]
92
93[variablelist
94[[`#define BOOST_NVP(object) see below`]
95[Expands to `boost::make_nvp(BOOST_STRINGIZE(object), object)`.]]]
96
97[endsect]
98
99[endsect]
100
101[section History]
102
103Robert Ramey originally implemented NVP in the Serialization library. Glen
104Fernandes implemented this new (but compatible) version in the Core library.
105
106[endsect]
107
108[endsect]
109