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key_context.hpp
1 
2 // Copyright 2014 MongoDB Inc.
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 
16 #pragma once
17 
18 #include <bsoncxx/builder/core.hpp>
19 #include <bsoncxx/builder/stream/closed_context.hpp>
20 #include <bsoncxx/builder/stream/value_context.hpp>
21 #include <bsoncxx/stdx/string_view.hpp>
22 #include <bsoncxx/stdx/type_traits.hpp>
23 
24 #include <bsoncxx/config/prelude.hpp>
25 
26 namespace bsoncxx {
27 inline namespace v_noabi {
28 namespace builder {
29 namespace stream {
30 
48 template <class base = closed_context>
49 class key_context {
50  public:
57  key_context(core* core) : _core(core) {}
58 
68  template <std::size_t n>
69  BSONCXX_INLINE value_context<key_context> operator<<(const char (&v)[n]) {
70  _core->key_view(stdx::string_view{v, n - 1});
71  return value_context<key_context>(_core);
72  }
73 
83  BSONCXX_INLINE value_context<key_context> operator<<(std::string str) {
84  _core->key_owned(std::move(str));
85  return value_context<key_context>(_core);
86  }
87 
97  BSONCXX_INLINE value_context<key_context> operator<<(stdx::string_view str) {
98  _core->key_view(std::move(str));
99  return value_context<key_context>(_core);
100  }
101 
110  template <typename T>
111  BSONCXX_INLINE detail::requires_t<key_context&, detail::is_invocable<T, key_context>> //
112  operator<<(T&& func) {
113  detail::invoke(std::forward<T>(func), *this);
114  return *this;
115  }
116 
127  template <typename T>
128  BSONCXX_INLINE detail::requires_t<bsoncxx::document::value,
129  std::is_same<base, closed_context>,
130  detail::is_alike<T, finalize_type>>
131  operator<<(T&&) {
132  return _core->extract_document();
133  }
134 
144  BSONCXX_INLINE key_context operator<<(concatenate_doc doc) {
145  _core->concatenate(doc);
146  return *this;
147  }
148 
154  BSONCXX_INLINE base operator<<(const close_document_type) {
155  _core->close_document();
156  return unwrap();
157  }
158 
163  BSONCXX_INLINE operator key_context<>() {
164  return key_context<>(_core);
165  }
166 
167  private:
168  BSONCXX_INLINE base unwrap() {
169  return base(_core);
170  }
171 
172  core* _core;
173 };
174 
175 } // namespace stream
176 } // namespace builder
177 } // namespace v_noabi
178 } // namespace bsoncxx
179 
180 #include <bsoncxx/config/postlude.hpp>
A low-level interface for constructing BSON documents and arrays.
Definition: core.hpp:43
core & key_owned(std::string key)
Appends a key passed as an STL string.
core & concatenate(const document::view &view)
Appends the keys from a BSON document into this BSON datum.
document::value extract_document()
Transfers ownership of the underlying document to the caller.
core & close_document()
Closes the current sub-document within this BSON datum.
core & key_view(stdx::string_view key)
Appends a key passed as a non-owning stdx::string_view.
A stream context which expects a key, which can later be followed by value, then more key/value pairs...
Definition: key_context.hpp:49
value_context< key_context > operator<<(const char(&v)[n])
<< operator for accepting a literal key and appending it to the core builder.
Definition: key_context.hpp:69
key_context operator<<(concatenate_doc doc)
<< operator for concatenating another document.
Definition: key_context.hpp:144
base operator<<(const close_document_type)
<< operator for closing a subdocument in the core builder.
Definition: key_context.hpp:154
key_context(core *core)
Create a key_context given a core builder.
Definition: key_context.hpp:57
A stream context which expects a value, which can later be followed by more key/value pairs.
Definition: value_context.hpp:48
The top-level namespace for bsoncxx library entities.
Definition: element.hpp:24
Container to concatenate a document.
Definition: concatenate.hpp:30
The type of a stream manipulator to close a subdocument.
Definition: helpers.hpp:44