std::any an_object{ std::string("hello world") };
if (an_object.has_value()) {
std::cout << std::any_cast<std::string>(an_object) << '\n';
}
try {
std::any_cast<int>(an_object);
} catch(std::bad_any_cast&) {
std::cout << "Wrong type\n";
}
std::any_cast<std::string&>(an_object) = "42";
std::cout << std::any_cast<std::string>(an_object) << '\n';
Output
hello world
Wrong type
42