1
2// (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
3// Use, modification and distribution are subject to the Boost Software License,
4// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
5// http://www.boost.org/LICENSE_1_0.txt).
6//
7// See http://www.boost.org/libs/type_traits for most recent version including documentation.
8
9#ifndef BOOST_TT_HAS_NOTHROW_ASSIGN_HPP_INCLUDED
10#define BOOST_TT_HAS_NOTHROW_ASSIGN_HPP_INCLUDED
11
12#include <boost/type_traits/integral_constant.hpp>
13#include <boost/type_traits/intrinsics.hpp>
14
15#if !defined(BOOST_HAS_NOTHROW_ASSIGN) || defined(BOOST_MSVC) || defined(BOOST_INTEL)
16#include <boost/type_traits/has_trivial_assign.hpp>
17#if !defined(BOOST_NO_CXX11_NOEXCEPT) && !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
18#include <boost/type_traits/declval.hpp>
19#include <boost/type_traits/is_const.hpp>
20#include <boost/type_traits/is_volatile.hpp>
21#include <boost/type_traits/is_reference.hpp>
22#include <boost/type_traits/is_assignable.hpp>
23#include <boost/type_traits/add_reference.hpp>
24#include <boost/type_traits/remove_reference.hpp>
25#endif
26#endif
27#if defined(__GNUC__) || defined(__SUNPRO_CC)
28#include <boost/type_traits/is_const.hpp>
29#include <boost/type_traits/is_volatile.hpp>
30#include <boost/type_traits/is_assignable.hpp>
31#include <boost/type_traits/is_array.hpp>
32#ifdef BOOST_INTEL
33#include <boost/type_traits/is_pod.hpp>
34#endif
35#endif
36
37namespace boost {
38
39#if !defined(BOOST_HAS_NOTHROW_ASSIGN) && !defined(BOOST_NO_CXX11_NOEXCEPT) && !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
40
41 namespace detail
42 {
43 template <class T, bool b1, bool b2> struct has_nothrow_assign_imp{ static const bool value = false; };
44 template <class T> struct has_nothrow_assign_imp<T, false, true>{ static const bool value = noexcept(boost::declval<typename add_reference<T>::type>() = boost::declval<typename add_reference<T const>::type>()); };
45 template <class T, std::size_t N> struct has_nothrow_assign_imp<T[N], false, true>{ static const bool value = has_nothrow_assign_imp<T, false, true>::value; };
46 template <class T> struct has_nothrow_assign_imp<T[], false, true>{ static const bool value = has_nothrow_assign_imp<T, false, true>::value; };
47 }
48
49#endif
50
51 template <class T>
52 struct has_nothrow_assign : public integral_constant < bool,
53#ifndef BOOST_HAS_NOTHROW_ASSIGN
54#if !defined(BOOST_NO_CXX11_NOEXCEPT) && !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
55 // Portable C++11 version:
56 detail::has_nothrow_assign_imp<T,
57 (is_const<typename remove_reference<T>::type>::value || is_volatile<typename remove_reference<T>::type>::value || is_reference<T>::value),
58 is_assignable<typename add_reference<T>::type, typename add_reference<const T>::type>::value
59 >::value
60#else
61 ::boost::has_trivial_assign<T>::value
62#endif
63#else
64 BOOST_HAS_NOTHROW_ASSIGN(T)
65#endif
66 > {};
67
68template <class T, std::size_t N> struct has_nothrow_assign <T[N]> : public has_nothrow_assign<T> {};
69template <> struct has_nothrow_assign<void> : public false_type{};
70template <class T> struct has_nothrow_assign<T volatile> : public false_type{};
71template <class T> struct has_nothrow_assign<T&> : public false_type{};
72#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
73template <class T> struct has_nothrow_assign<T&&> : public false_type{};
74#endif
75#ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
76template <> struct has_nothrow_assign<void const> : public false_type{};
77template <> struct has_nothrow_assign<void const volatile> : public false_type{};
78template <> struct has_nothrow_assign<void volatile> : public false_type{};
79#endif
80
81} // namespace boost
82
83#endif // BOOST_TT_HAS_NOTHROW_ASSIGN_HPP_INCLUDED
84