1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
// PR c++/56998 class Secret; char IsNullLiteralHelper(Secret* p); char (&IsNullLiteralHelper(...))[2]; struct C { int val() { return 42; } }; template <typename T> unsigned f() { return sizeof(IsNullLiteralHelper(C().val())); }