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// (C) Copyright 2016 Ashish Sadanandan
14// Use, modification and distribution is subject to the Boost Software
15// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
16// http://www.boost.org/LICENSE_1_0.txt)
17
18// See http://www.boost.org/libs/serialization for updates, documentation, and revision history.
19
20// macro used to implement a strong typedef. strong typedef
21// guarentees that two types are distinguised even though the
22// share the same underlying implementation. typedef does not create
23// a new type. BOOST_STRONG_TYPEDEF(T, D) creates a new type named D
24// that operates as a type T.
25
26#include <boost/config.hpp>
27#include <boost/operators.hpp>
28#include <boost/type_traits/has_nothrow_assign.hpp>
29#include <boost/type_traits/has_nothrow_constructor.hpp>
30#include <boost/type_traits/has_nothrow_copy.hpp>
31
32#define BOOST_STRONG_TYPEDEF(T, D) \
33struct D \
34 : boost::totally_ordered1< D \
35 , boost::totally_ordered2< D, T \
36 > > \
37{ \
38 T t; \
39 explicit D(const T& t_) BOOST_NOEXCEPT_IF(boost::has_nothrow_copy_constructor<T>::value) : t(t_) {} \
40 D() BOOST_NOEXCEPT_IF(boost::has_nothrow_default_constructor<T>::value) : t() {} \
41 D(const D & t_) BOOST_NOEXCEPT_IF(boost::has_nothrow_copy_constructor<T>::value) : t(t_.t) {} \
42 D& operator=(const D& rhs) BOOST_NOEXCEPT_IF(boost::has_nothrow_assign<T>::value) {t = rhs.t; return *this;} \
43 D& operator=(const T& rhs) BOOST_NOEXCEPT_IF(boost::has_nothrow_assign<T>::value) {t = rhs; return *this;} \
44 operator const T&() const {return t;} \
45 operator T&() {return t;} \
46 bool operator==(const D& rhs) const {return t == rhs.t;} \
47 bool operator<(const D& rhs) const {return t < rhs.t;} \
48};
49
50#endif // BOOST_SERIALIZATION_STRONG_TYPEDEF_HPP
51

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