gcc/testsuite/g++.dg/cpp1z/fold5.C

// Test that we complain about fold-expressions in C++11 and C++14.
// { dg-do compile { target { c++11 && { ! c++17 } } } }

template <class...T>
constexpr int f(T... t)
{
  return (... + t);		// { dg-error "fold" }
}