Is the GNU C++ library missing an unordered_map constructor?

Question

At least one C++ reference lists following constructor signature:

explicit unordered_map ( const allocator_type& alloc );

It seems that it is not included in /usr/include/c++/4.8.2/bits/unordered_map.h , though. At least I can't spot it and the compiler can't find it, as well.

Thus, my question: Is this constructor specified by the C++ standard? Is the GNU C++ library implementation of unordered_map violating the standard in that respect?

Answer 1

Is this constructor specified by the C++ standard?

Yes.

Is the GNU C++ library implementation of unordered_map violating the standard in that respect?

Yes.