constexpr bool is_boolean() const noexcept;
This function returns #!cpp true
if and only if the JSON value is #!json true
or #!json false
.
#!cpp true
if type is boolean, #!cpp false
otherwise.
No-throw guarantee: this member function never throws exceptions.
Constant.
??? example
The following code exemplifies `is_boolean()` for all JSON types. ```cpp --8<-- "examples/is_boolean.cpp" ``` Output: ```json --8<-- "examples/is_boolean.output" ```