1#ifndef BOOST_SERIALIZATION_STRONG_TYPEDEF_HPP
2#define BOOST_SERIALIZATION_STRONG_TYPEDEF_HPP
3
4// MS compatible compilers support #pragma once
5#if defined(_MSC_VER)
6# pragma once
7#endif
8
9/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
10// strong_typedef.hpp:
11
12// (C) Copyright 2002 Robert Ramey - http://www.rrsd.com .
13// Use, modification and distribution is subject to the Boost Software
14// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
15// http://www.boost.org/LICENSE_1_0.txt)
16
17// See http://www.boost.org/libs/serialization for updates, documentation, and revision history.
18
19// macro used to implement a strong typedef. strong typedef
20// guarentees that two types are distinguised even though the
21// share the same underlying implementation. typedef does not create
22// a new type. BOOST_STRONG_TYPEDEF(T, D) creates a new type named D
23// that operates as a type T.
24
25#include <boost/config.hpp>
26#include <boost/operators.hpp>
27
28#define BOOST_STRONG_TYPEDEF(T, D) \
29struct D \
30 : boost::totally_ordered1< D \
31 , boost::totally_ordered2< D, T \
32 > > \
33{ \
34 T t; \
35 explicit D(const T t_) : t(t_) {}; \
36 D(): t() {}; \
37 D(const D & t_) : t(t_.t){} \
38 D & operator=(const D & rhs) { t = rhs.t; return *this;} \
39 D & operator=(const T & rhs) { t = rhs; return *this;} \
40 operator const T & () const {return t; } \
41 operator T & () { return t; } \
42 bool operator==(const D & rhs) const { return t == rhs.t; } \
43 bool operator<(const D & rhs) const { return t < rhs.t; } \
44};
45
46#endif // BOOST_SERIALIZATION_STRONG_TYPEDEF_HPP
47

source code of boost/boost/serialization/strong_typedef.hpp