C++

28.10    “any” Holds Any Type

If you are dissatisfied with having to specify the possible types when declaring variant, then perhaps any is for you. You can store a value of any type in it. And you can only retrieve that type. If you try with a different type, you will get an exception. However, you can assign any a new value and also a new type:

// https://godbolt.org/z/1eco9Wcr3#include <any>#include <iostream>#include <vector>#include <string>int main() {    std::any a = 5;    std::cout << std::any_cast<int>(a) << '\n';    a = 3.456;    std::cout << std::any_cast<double>(a) << '\n';    using namespace std::literals;    std::vector<std::any> data { 4, 8.976, "Geronimo"s };    std::cout << std::any_cast<double>( data[1] ) << '\n';    std::cout << data[1].type().