// Deduction from inherited constructors isn't supported before C++23. //{ dg-do compile { target c++17 } } template <class T> struct A { A(T); }; template <class T> struct B: A<T> { using A<T>::A; }; int main() { B b = 42; // { dg-line init } // { dg-prune-output "no matching function" } // { dg-error "class template argument deduction" "" { target c++20_down } init } }