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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/util/functor.hpp>
23 
24 #include <bsoncxx/config/prelude.hpp>
25 
26 namespace bsoncxx {
27 BSONCXX_INLINE_NAMESPACE_BEGIN
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
112  typename std::enable_if<util::is_functor<T, void(key_context<>)>::value, key_context>::type&
113  operator<<(T&& func) {
114  func(*this);
115  return *this;
116  }
117 
129  template <typename T>
130  BSONCXX_INLINE typename std::enable_if<
131  std::is_same<base, closed_context>::value &&
132  std::is_same<typename std::remove_reference<T>::type, const finalize_type>::value,
133  // TODO(MSVC): This should just be 'document::value', but
134  // VS2015U1 can't resolve the name.
136  operator<<(T&&) {
137  return _core->extract_document();
138  }
139 
149  BSONCXX_INLINE key_context operator<<(concatenate_doc doc) {
150  _core->concatenate(doc);
151  return *this;
152  }
153 
160  BSONCXX_INLINE base operator<<(const close_document_type) {
161  _core->close_document();
162  return unwrap();
163  }
164 
169  BSONCXX_INLINE operator key_context<>() {
170  return key_context<>(_core);
171  }
172 
173  private:
174  BSONCXX_INLINE base unwrap() {
175  return base(_core);
176  }
177 
178  core* _core;
179 };
180 
181 } // namespace stream
182 } // namespace builder
183 BSONCXX_INLINE_NAMESPACE_END
184 } // namespace bsoncxx
185 
186 #include <bsoncxx/config/postlude.hpp>
bsoncxx::builder::core::extract_document
document::value extract_document()
Transfers ownership of the underlying document to the caller.
bsoncxx::builder::stream::value_context
A stream context which expects a value, which can later be followed by more key/value pairs.
Definition: value_context.hpp:48
bsoncxx
Top level namespace for MongoDB C++ BSON functionality.
Definition: element.hpp:24
bsoncxx::builder::core::key_owned
core & key_owned(std::string key)
Appends a key passed as an STL string.
bsoncxx::builder::stream::key_context::operator<<
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
bsoncxx::builder::stream::key_context::operator<<
key_context operator<<(concatenate_doc doc)
<< operator for concatenating another document.
Definition: key_context.hpp:149
bsoncxx::builder::concatenate_doc
Container to concatenate a document.
Definition: concatenate.hpp:30
bsoncxx::builder::stream::finalize_type
The type of a stream manipulator to finalize a document.
Definition: helpers.hpp:83
bsoncxx::document::value
A read-only BSON document that owns its underlying buffer.
Definition: value.hpp:34
bsoncxx::builder::core::key_view
core & key_view(stdx::string_view key)
Appends a key passed as a non-owning stdx::string_view.
bsoncxx::builder::core
A low-level interface for constructing BSON documents and arrays.
Definition: core.hpp:42
bsoncxx::type
type
An enumeration of each BSON type.
Definition: types.hpp:46
bsoncxx::builder::stream::key_context::operator<<
base operator<<(const close_document_type)
<< operator for closing a subdocument in the core builder.
Definition: key_context.hpp:160
bsoncxx::builder::core::concatenate
core & concatenate(const document::view &view)
Appends the keys from a BSON document into this BSON datum.
bsoncxx::builder::core::close_document
core & close_document()
Closes the current sub-document within this BSON datum.
bsoncxx::builder::stream::close_document_type
The type of a stream manipulator to close a subdocument.
Definition: helpers.hpp:44
bsoncxx::builder::stream::key_context<>
bsoncxx::builder::stream::key_context::key_context
key_context(core *core)
Create a key_context given a core builder.
Definition: key_context.hpp:57