queue template constructors uncallable

[tamboril]

Using queue with an allocator, it is impossible to write code that invokes this template constructor:

template <typename U>
    queue(size_type n, typename node_allocator::template rebind<U>::other const & alloc):

(or the other one with the rebind).

The template argument U cannot be deduced (at least with gcc 5.3.0).

I had to add the following form in order to use this with a custom allocator:

explicit queue(size_type n, allocator const & alloc)

I notice that the constructor that takes only an alloc already has this overload.

[star-e]

This problem is still not fixed in boost 1.69, with msvc2019 v142.
Using custom allocator with lockfree::fixed_sized is impossible.