[ 2017-03-12, post-Kona ]

Resolved by P0433R2.

The three container adapters should each have a deduction guide allowing the deduction of the value type T from the supplied container, potentially constrained to avoid confusion with deduction from a copy/move constructor.

Proposed change: For each container adapter, add a deduction guide of the form

template <class Container>
adapter(const Container&) -> adapter<typename Container::value_type, Container>;