#include required to use initializer list in range-based for?

Question

The final C++11 standard includes provisions for range-based for to \"just work\" for native arrays without having to include or any other head

Answer 1

GCC 7.1 produces the following error if <initializer_list> is not included:

error: deducing from brace-enclosed initializer list requires #include <initializer_list>
     for (auto i : { 1, 2, 3, 4, 5 })
                                   ^

To see this error one should omit <iostream>, because including <iostream> will also include <initializer_list>.

Answer 2

I'd say yes. According to §6.5.4[stmt.ranged]/1, the statement

for (auto i : { 1, 2, 3, 4, 5 })
    ...

is just equivalent to

auto&& __range = { 1, 2, 3, 4, 5 };
...

and that means an initializer_list<int> is used, and the <initializer_list> header needs to be included.