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value_context.hpp
1 // Copyright 2014 MongoDB Inc.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #pragma once
16 
17 #include <bsoncxx/builder/stream/value_context-fwd.hpp>
18 
19 #include <bsoncxx/builder/core.hpp>
20 #include <bsoncxx/builder/stream/array_context.hpp>
21 #include <bsoncxx/builder/stream/closed_context.hpp>
22 #include <bsoncxx/builder/stream/helpers.hpp>
23 #include <bsoncxx/stdx/type_traits.hpp>
24 
25 #include <bsoncxx/config/prelude.hpp>
26 
27 namespace bsoncxx {
28 namespace v_noabi {
29 namespace builder {
30 namespace stream {
31 
49 template <class base>
51  public:
58  BSONCXX_INLINE value_context(core* core) : _core(core) {}
59 
67  template <class T>
68  BSONCXX_INLINE detail::requires_not_t<base, detail::is_invocable<T, single_context>> //
69  operator<<(T&& t) {
70  _core->append(std::forward<T>(t));
71  return unwrap();
72  }
73 
81  template <typename T>
82  BSONCXX_INLINE detail::requires_t<base, detail::is_invocable<T, single_context>> //
83  operator<<(T&& func) {
84  detail::invoke(std::forward<T>(func), *this);
85  return unwrap();
86  }
87 
93  BSONCXX_INLINE key_context<base> operator<<(const open_document_type) {
94  _core->open_document();
95  return wrap_document();
96  }
97 
103  BSONCXX_INLINE array_context<base> operator<<(const open_array_type) {
104  _core->open_array();
105  return wrap_array();
106  }
107 
113  operator single_context();
114 
115 #if !defined(_MSC_VER) && !defined(__INTEL_COMPILER)
116  // TODO(MSVC): Causes an ICE under VS2015U1
117  static_assert(
118  std::is_same<value_context, decltype(std::declval<value_context>() << 1 << "str")>::value,
119  "value_context must be templatized on a key_context");
120 #endif
121 
122  private:
123  BSONCXX_INLINE base unwrap() {
124  return base(_core);
125  }
126 
127  BSONCXX_INLINE array_context<base> wrap_array() {
128  return array_context<base>(_core);
129  }
130 
131  BSONCXX_INLINE key_context<base> wrap_document() {
132  return key_context<base>(_core);
133  }
134 
135  core* _core;
136 };
137 
138 } // namespace stream
139 } // namespace builder
140 } // namespace v_noabi
141 } // namespace bsoncxx
142 
143 #include <bsoncxx/config/postlude.hpp>
A low-level interface for constructing BSON documents and arrays.
Definition: core.hpp:45
core & append(const types::b_double &value)
Appends a BSON double.
core & open_array()
Opens a sub-array within this BSON datum.
core & open_document()
Opens a sub-document within this BSON datum.
A stream context which expects a value, which can later be followed by more key/value pairs.
Definition: value_context.hpp:50
detail::requires_not_t< base, detail::is_invocable< T, single_context > > operator<<(T &&t)
<< operator for accepting a real value and appending it to the core builder.
Definition: value_context.hpp:69
value_context(core *core)
Create a value_context given a core builder.
Definition: value_context.hpp:58
The top-level namespace for bsoncxx library entities.
Definition: element-fwd.hpp:19