When should I use std::any

Question

Since C++17 std::any is introduced. One can now write code like this

#include 
#include 
#include 

int         


        

Answer 1

It's used in Wt, to provide a non-template interface for tabular data.

There are conversions to string for builtin and Wt types, and you can register additional conversions by specialising Wt::any_traits. This allows anything to be displayed as an entry in a table, the view classes don't have to know anything about the types they are displaying.