using boolean_t = BooleanType;
The type used to store JSON booleans.
RFC 8259 implicitly describes a boolean as a type which differentiates the two literals #!json true and #!json false.
To store boolean values in C++, a type is defined by the template parameter BooleanType which chooses the type to use.
With the default values for BooleanType (#!cpp bool), the default value for boolean_t is #!cpp bool.
Boolean values are stored directly inside a basic_json type.
??? example
The following code shows that `boolean_t` is by default, a typedef to `#!cpp bool`. ```cpp --8<-- "examples/boolean_t.cpp" ``` Output: ```json --8<-- "examples/boolean_t.output" ```