File: pointer_traits_sfinae_test.cpp

package info (click to toggle)
boost1.90 1.90.0-1
  • links: PTS, VCS
  • area: main
  • in suites:
  • size: 593,120 kB
  • sloc: cpp: 4,190,908; xml: 196,648; python: 34,618; ansic: 23,145; asm: 5,468; sh: 3,774; makefile: 1,161; perl: 1,020; sql: 728; ruby: 676; yacc: 478; java: 77; lisp: 24; csh: 6
file content (108 lines) | stat: -rw-r--r-- 3,117 bytes parent folder | download | duplicates (8)
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
/*
Copyright 2021 Glen Joseph Fernandes
(glenjofe@gmail.com)

Distributed under the Boost Software License, Version 1.0.
(http://www.boost.org/LICENSE_1_0.txt)
*/
#include <boost/core/pointer_traits.hpp>
#include <boost/core/lightweight_test.hpp>

template<class>
struct valid {
    typedef void type;
};

template<class, class = void>
struct has_pointer {
    static const bool value = false;
};

template<class T>
struct has_pointer<T, typename valid<typename T::pointer>::type> {
    static const bool value = true;
};

template<class, class = void>
struct has_element_type {
    static const bool value = false;
};

template<class T>
struct has_element_type<T, typename valid<typename T::element_type>::type> {
    static const bool value = true;
};

template<class, class = void>
struct has_difference_type {
    static const bool value = false;
};

template<class T>
struct has_difference_type<T,
    typename valid<typename T::difference_type>::type> {
    static const bool value = true;
};

template<class, class, class = void>
struct has_rebind_to_type {
    static const bool value = false;
};

template<class T, class U>
struct has_rebind_to_type<T, U,
    typename valid<typename T::template rebind_to<U>::type>::type> {
    static const bool value = true;
};

struct P1 { };

struct P2 {
    typedef int element_type;
};

struct P3 {
    typedef int element_type;

#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
    template<class>
    using rebind = P3;
#else
    template<class>
    struct rebind {
        typedef P3 other;
    };
#endif
};

template<class T>
struct S {
    typedef T element_type;
};

typedef S<int> P4;

int main()
{
    BOOST_TEST(!has_pointer<boost::pointer_traits<P1> >::value);
    BOOST_TEST(!has_element_type<boost::pointer_traits<P1> >::value);
    BOOST_TEST(!has_difference_type<boost::pointer_traits<P1> >::value);
    BOOST_TEST((!has_rebind_to_type<boost::pointer_traits<P1>, char>::value));
    BOOST_TEST(has_pointer<boost::pointer_traits<P2> >::value);
    BOOST_TEST(has_element_type<boost::pointer_traits<P2> >::value);
    BOOST_TEST(has_difference_type<boost::pointer_traits<P2> >::value);
    BOOST_TEST((!has_rebind_to_type<boost::pointer_traits<P2>, char>::value));
    BOOST_TEST(has_pointer<boost::pointer_traits<P3> >::value);
    BOOST_TEST(has_element_type<boost::pointer_traits<P3> >::value);
    BOOST_TEST(has_difference_type<boost::pointer_traits<P3> >::value);
    BOOST_TEST((has_rebind_to_type<boost::pointer_traits<P3>, char>::value));
    BOOST_TEST(has_pointer<boost::pointer_traits<P4> >::value);
    BOOST_TEST(has_element_type<boost::pointer_traits<P4> >::value);
    BOOST_TEST(has_difference_type<boost::pointer_traits<P4> >::value);
    BOOST_TEST((has_rebind_to_type<boost::pointer_traits<P4>, char>::value));
    BOOST_TEST(has_pointer<boost::pointer_traits<int*> >::value);
    BOOST_TEST(has_element_type<boost::pointer_traits<int*> >::value);
    BOOST_TEST(has_difference_type<boost::pointer_traits<int*> >::value);
    BOOST_TEST((has_rebind_to_type<boost::pointer_traits<int*>, char>::value));
    return boost::report_errors();
}