#include using namespace nlohmann; int main() { // create JSON values json j_null; json j_boolean = true; json j_number_integer = 17; json j_number_float = 23.42; json j_object = {{"one", 1}, {"two", 2}}; json j_array = {1, 2, 4, 8, 16}; json j_string = "Hello, world"; // call is_boolean() std::cout << std::boolalpha; std::cout << j_null.is_boolean() << '\n'; std::cout << j_boolean.is_boolean() << '\n'; std::cout << j_number_integer.is_boolean() << '\n'; std::cout << j_number_float.is_boolean() << '\n'; std::cout << j_object.is_boolean() << '\n'; std::cout << j_array.is_boolean() << '\n'; std::cout << j_string.is_boolean() << '\n'; }