aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/restricted/nlohmann_json/include/nlohmann/detail/json_ref.hpp
blob: b4e5dabaf7973a029e4c568daf254e58342658d2 (plain) (blame)
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
#pragma once

#include <initializer_list>
#include <utility>

#include <nlohmann/detail/meta/type_traits.hpp>

namespace nlohmann
{
namespace detail
{
template<typename BasicJsonType>
class json_ref
{
  public:
    using value_type = BasicJsonType;

    json_ref(value_type&& value)
        : owned_value(std::move(value))
    {}

    json_ref(const value_type& value)
        : value_ref(&value)
    {}

    json_ref(std::initializer_list<json_ref> init)
        : owned_value(init)
    {}

    template <
        class... Args,
        enable_if_t<std::is_constructible<value_type, Args...>::value, int> = 0 >
    json_ref(Args && ... args)
        : owned_value(std::forward<Args>(args)...)
    {}

    // class should be movable only
    json_ref(json_ref&&) noexcept = default;
    json_ref(const json_ref&) = delete;
    json_ref& operator=(const json_ref&) = delete;
    json_ref& operator=(json_ref&&) = delete;
    ~json_ref() = default;

    value_type moved_or_copied() const
    {
        if (value_ref == nullptr)
        {
            return std::move(owned_value);
        }
        return *value_ref;
    }

    value_type const& operator*() const
    {
        return value_ref ? *value_ref : owned_value;
    }

    value_type const* operator->() const
    {
        return &** this;
    }

  private:
    mutable value_type owned_value = nullptr;
    value_type const* value_ref = nullptr;
};
}  // namespace detail
}  // namespace nlohmann