#include < iostream >
template< class T >
T func1(T t) { return t; }
auto func2(auto t) { return t; }
int main() {
std::cout << func1(1) << func1(2.2) << func2(3) << func2(4.4);
}
autoauto.cpp:6:18: note: deduced return type only available with -std=c++1y or -std=gnu++1y
g++ --std=c++14 autoauto.cpp ./a.out 12.234.4