auto type deduction

[milos94]

Maybe my understanding of concepts is not good enough, but I'm having this issue. https://godbolt.org/z/ThKZu5 As seen in the example parameter declared as Employee auto && is deduced as Employee auto (because of std::decay_t) instead of CT::CTEmployee. The commented out version works fine, where concepts are template parameters. So my question is does the type deduction not happen here? Or better when does evaluation of concepts happen?

[uap-universe]

Please verify, if I correctly minimized your example to pin down the issue. https://godbolt.org/z/OzT00u

[milos94]

Yes, that's about it (sorry I didn't post something like this originally). Don't know if it helps but having a concrete type, or template argument, as type for the first parameter works fine. eg. template<typename T> void fun(T&& x, Bar<std::decay_t<decltype(x)>> auto & y); template <Foo F> void fun(F&& x, Bar<std::decay_t<decltype(x)>> auto & y) { } void fun(FooImpl & x, Bar<std::decay_t<decltype(x)>> auto & y); So it seems that it's auto that's causing issues.