ceph/src/jaegertracing/opentelemetry-cpp/third_party/nlohmann-json/doc/mkdocs/docs/api/basic_json/boolean_t.md

   1 # <small>nlohmann::basic_json::</small>boolean_t
   2
   3 ```cpp
   4 using boolean_t = BooleanType;
   5 ```
   6
   7 The type used to store JSON booleans.
   8
   9 [RFC 8259](https://tools.ietf.org/html/rfc8259) implicitly describes a boolean as a type which differentiates the two literals
  10 `#!json true` and `#!json false`.
  11
  12 To store objects in C++, a type is defined by the template parameter  `BooleanType` which chooses the type to use.
  13
  14 ## Notes
  15
  16 #### Default type
  17
  18 With the default values for `BooleanType` (`#!cpp bool`), the default value for `boolean_t` is `#!cpp bool`.
  19
  20 #### Storage
  21
  22 Boolean values are stored directly inside a `basic_json` type.
  23
  24 ## Examples
  25
  26 ??? example
  27
  28     The following code shows that `boolean_t` is by default, a typedef to `#!cpp bool`.
  29
  30     ```cpp
  31     --8<-- "examples/boolean_t.cpp"
  32     ```
  33
  34     Output:
  35
  36     ```json
  37     --8<-- "examples/boolean_t.output"
  38     ```
  39
  40 ## Version history
  41
  42 - Added in version 1.0.0.