std::variants#include <x/visitor.H> struct one{}; struct two{}; void foo(const std::variant<one, two> &bar) { std::visit( x::visitor{ [](const one &o) {}, [](const two &t) {} }, bar); }
The x::visitor template
constructs a callable object for passing to
std::visit. The intended usage is to pass
a variadic list of lambdas to the template, using uniform initialization
syntax. This constructs a callable object that inherits all passed lambas,
which then gets passed to std::visit.