gcc/testsuite/g++.dg/cpp0x/sfinae15.C

// PR c++/48531
// { dg-do compile { target c++11 } }

template<class T,
  class = decltype(T())
>
char f(int);

template<class>
char (&f(...))[2];

static_assert(sizeof(f<int[]>(0)) != 1, "Error");