/src/boost/boost/json/impl/visit.hpp
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1 | | // |
2 | | // Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com) |
3 | | // |
4 | | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
5 | | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
6 | | // |
7 | | // Official repository: https://github.com/boostorg/json |
8 | | // |
9 | | |
10 | | #ifndef BOOST_JSON_IMPL_VISIT_HPP |
11 | | #define BOOST_JSON_IMPL_VISIT_HPP |
12 | | |
13 | | namespace boost { |
14 | | namespace json { |
15 | | |
16 | | namespace detail { |
17 | | |
18 | | extern |
19 | | BOOST_JSON_DECL |
20 | | std::nullptr_t stable_np; |
21 | | |
22 | | } // namespace detail |
23 | | |
24 | | template<class Visitor> |
25 | | auto |
26 | | visit( |
27 | | Visitor&& v, |
28 | | value& jv) -> decltype( |
29 | | static_cast<Visitor&&>(v)( std::declval<std::nullptr_t&>() ) ) |
30 | | { |
31 | | switch(jv.kind()) |
32 | | { |
33 | | default: // unreachable()? |
34 | | case kind::string: return static_cast<Visitor&&>(v)( jv.get_string() ); |
35 | | case kind::array: return static_cast<Visitor&&>(v)( jv.get_array() ); |
36 | | case kind::object: return static_cast<Visitor&&>(v)( jv.get_object() ); |
37 | | case kind::bool_: return static_cast<Visitor&&>(v)( jv.get_bool() ); |
38 | | case kind::int64: return static_cast<Visitor&&>(v)( jv.get_int64() ); |
39 | | case kind::uint64: return static_cast<Visitor&&>(v)( jv.get_uint64() ); |
40 | | case kind::double_: return static_cast<Visitor&&>(v)( jv.get_double() ); |
41 | | case kind::null: return static_cast<Visitor&&>(v)( detail::stable_np ) ; |
42 | | } |
43 | | } |
44 | | |
45 | | template<class Visitor> |
46 | | auto |
47 | | visit( |
48 | | Visitor&& v, |
49 | | value const& jv) -> decltype( |
50 | | static_cast<Visitor&&>(v)( std::declval<std::nullptr_t const&>() ) ) |
51 | 0 | { |
52 | 0 | detail::scalar const& sc = detail::access::get_scalar(jv); |
53 | 0 | switch(jv.kind()) |
54 | 0 | { |
55 | 0 | default: // unreachable()? |
56 | 0 | case kind::string: return static_cast<Visitor&&>(v)( jv.get_string() ); |
57 | 0 | case kind::array: return static_cast<Visitor&&>(v)( jv.get_array() ); |
58 | 0 | case kind::object: return static_cast<Visitor&&>(v)( jv.get_object() ); |
59 | | // local variables work around a bug in older clangs |
60 | 0 | case kind::bool_: { |
61 | 0 | bool const& b = sc.b; |
62 | 0 | return static_cast<Visitor&&>(v)(b); |
63 | 0 | } |
64 | 0 | case kind::int64: { |
65 | 0 | std::int64_t const& i = sc.i; |
66 | 0 | return static_cast<Visitor&&>(v)(i); |
67 | 0 | } |
68 | 0 | case kind::uint64: { |
69 | 0 | std::uint64_t const& u = sc.u; |
70 | 0 | return static_cast<Visitor&&>(v)(u); |
71 | 0 | } |
72 | 0 | case kind::double_: { |
73 | 0 | double const& d = sc.d; |
74 | 0 | return static_cast<Visitor&&>(v)(d); |
75 | 0 | } |
76 | 0 | case kind::null: { |
77 | 0 | auto const& np = detail::stable_np; |
78 | 0 | return static_cast<Visitor&&>(v)(np) ; |
79 | 0 | } |
80 | 0 | } |
81 | 0 | } |
82 | | |
83 | | |
84 | | template<class Visitor> |
85 | | auto |
86 | | visit( |
87 | | Visitor&& v, |
88 | | value&& jv) -> decltype( |
89 | | static_cast<Visitor&&>(v)( std::declval<std::nullptr_t&&>() ) ) |
90 | | { |
91 | | switch(jv.kind()) |
92 | | { |
93 | | default: // unreachable()? |
94 | | case kind::string: return static_cast<Visitor&&>(v)(std::move( jv.get_string() )); |
95 | | case kind::array: return static_cast<Visitor&&>(v)(std::move( jv.get_array() )); |
96 | | case kind::object: return static_cast<Visitor&&>(v)(std::move( jv.get_object() )); |
97 | | case kind::bool_: return static_cast<Visitor&&>(v)(std::move( detail::access::get_scalar(jv).b )); |
98 | | case kind::int64: return static_cast<Visitor&&>(v)(std::move( detail::access::get_scalar(jv).i )); |
99 | | case kind::uint64: return static_cast<Visitor&&>(v)(std::move( detail::access::get_scalar(jv).u )); |
100 | | case kind::double_: return static_cast<Visitor&&>(v)(std::move( detail::access::get_scalar(jv).d )); |
101 | | case kind::null: return static_cast<Visitor&&>(v)(std::move( detail::stable_np )) ; |
102 | | } |
103 | | } |
104 | | |
105 | | } // namespace json |
106 | | } // namespace boost |
107 | | |
108 | | #endif |