How to filter duplicate types from tuple C++

Question

How does one filter duplicate types from a tuple?

For example:

using Tuple = std::tuple
usi         


        

Answer 1

#include 
#include 

template 
struct unique : std::type_identity {};

template 
struct unique, U, Us...>
    : std::conditional_t<(std::is_same_v || ...)
                       , unique, Us...>
                       , unique, Us...>> {};

template 
using unique_tuple = typename unique, Ts...>::type;

DEMO