#include #include int main() { std::cout << std::boolalpha; // the default constructor is the only public one: it creates an invalid // (discarded) view, useful as a "no value yet" placeholder nlohmann::json_view v; std::cout << v.is_discarded() << '\n'; // views are trivially copyable handles (two pointers); the document owns // the actual data nlohmann::json_view copy = v; std::cout << copy.is_discarded() << '\n'; }