json/api/basic_json/boolean_t/index.md

nlohmann::basic_json::boolean_t

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 true and false.

To store boolean values in C++, a type is defined by the template parameter BooleanType which chooses the type to use.

Notes

Default type

With the default values for BooleanType (bool), the default value for boolean_t is bool.

Storage

Boolean values are stored directly inside a basic_json type.

Examples

Example

The following code shows that boolean_t is by default, a typedef to bool.

#include <iostream>
#include <iomanip>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

int main()
{
    std::cout << std::boolalpha << std::is_same<bool, json::boolean_t>::value << std::endl;
}

Output:

true

Version history

• Added in version 1.0.0.